t7410: 210 tests for various 'git submodule update' scenariosjh/submodule-tests

This is a work-in-progress to flesh out (and promote discussion about)
the expected behaviors for all possible scenarios in which
'git submodule update' might be run.

More details in the top of t/t7410-submodule-update-scenarios.sh

Cc: W. Trevor King <wking@tremily.us>
Cc: Jens Lehmann <Jens.Lehmann@web.de>
Cc: Heiko Voigt <hvoigt@hvoigt.net>
Cc: Junio C Hamano <gitster@pobox.com>

Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 2859 insertions, 0 deletions

diff --git a/t/t7410-submodule-update-scenarios.sh b/t/t7410-submodule-update-scenarios.sh
new file mode 100755
index 0000000000..22056cc1d0
--- /dev/null
+++ b/t/t7410-submodule-update-scenarios.sh
@@ -0,0 +1,2859 @@
+#!/bin/sh
+#
+# Copyright (c) 2014 Johan Herland
+#
+
+test_description='Test "git submodule update" in a variety of scenarios
+
+This test attempts to map out the various scenarios in which submodule update
+is run, and verify their expected behaviour (according to the git submodule
+documentation).
+'
+
+. ./test-lib.sh
+
+# First a textual representation of the various cases we are testing:
+#
+# The factors/variables being explored are:
+#  - submodule.sub.branch
+#     1.* - unset
+#     2.* - == foo (exists upstream)
+#     3.* - == bar (MISSING upstream)
+#  - submodule.sub.update
+#     ?.1.* - none
+#     ?.2.* - checkout
+#     ?.3.* - merge
+#     ?.4.* - rebase
+#     ?.5.* - !command
+#  - remote mode (whether or not --remote is given on command-line)
+#     ?.?.1.* - disabled
+#     ?.?.2.* - enabled
+#  - current state of submodule:
+#     ?.?.?.1 - not yet cloned
+#     ?.?.?.2 - cloned, detached, HEAD == gitlink
+#     ?.?.?.3 - cloned, detached, HEAD != gitlink
+#     ?.?.?.4 - cloned, on branch foo (exists upstream), HEAD == gitlink
+#     ?.?.?.5 - cloned, on branch foo (exists upstream), HEAD != gitlink
+#     ?.?.?.6 - cloned, on branch bar (MISSING upstream), HEAD == gitlink
+#     ?.?.?.7 - cloned, on branch bar (MISSING upstream), HEAD != gitlink
+#
+# The above variables are combined to enumerate all possible cases, from
+# 1.1.1.1 to 3.5.2.7 (yes, that's 210 separate test cases). Each test case is
+# named with its number followed by a short description of its expected outcome.
+
+# TODO ITEMS:
+#
+# T1: Rename "master" branch to "default" to test correct behaviour when
+#     submodule's upstream has no master branch.
+#     Affects: pre, 1.3.1.1, 1.3.2.1, 1.4.1.1, 1.4.2.1
+#
+# T2: Test with submodule.<name>.url != submodule's remote.origin.url. Does
+#     "submodule update --remote" sync with submodule.<name>.url, or with the
+#     submodule's origin? (or with the submodule's current branch's upstream)?
+#
+# T3: Fix uninitialized submodule state after attempting to clone from upstream
+#     where .branch is missing.
+#     Affects: pre, 3.2.2.1, 3.3.2.1, 3.4.2.1, 3.5.2.1
+
+# DISCUSSION ITEMS:
+#
+# D1: When submodule is already at right commit, checkout-mode currently does
+#     nothing. Should it instead detach, even when no update is needed?
+#     Affects: 1.2.1.4, 1.2.1.6, 2.2.1.4, 2.2.1.6, 3.2.1.4, 3.2.1.6
+#
+# D2: Should all/some of 1.3.*/1.4.* abort/error because we don't know what to
+#     merge/rebase with (because .branch is unset)? Or is the current default
+#     to origin/HEAD OK?
+#     Affects: 1.3.*, 1.4.*
+#
+# D3: When submodule is already at right commit, merge/rebase-mode currently
+#     does nothing. Should it do something else (e.g. not leave submodule
+#     detached, or checked out on the "wrong" branch (i.e. != .branch))?
+#     (This discussion point is related to D1, D5 and D6)
+#     Affects: 1.3.1.2, 1.3.1.4, 1.3.1.6,
+#              1.4.1.2, 1.4.1.4, 1.4.1.6,
+#              2.3.1.2, 2.3.1.4, 2.3.1.6, 2.3.2.3, 2.3.2.5, 2.3.2.7,
+#              2.4.1.2, 2.4.1.4, 2.4.1.6, 2.4.2.3, 2.4.2.5, 2.4.2.7,
+#              3.3.1.2, 3.3.1.4, 3.3.1.6
+#              3.4.1.2, 3.4.1.4, 3.4.1.6
+#
+# D4: When 'submodule update' performs a clone to populate a submodule, it
+#     currently also creates a default branch (named after origin/HEAD) in
+#     that submodule, EVEN WHEN THAT BRANCH WILL NEVER BE USED (e.g. because
+#     we're in checkout-mode and submodule will always be detached). Is this
+#     good, or should the clone performed by 'submodule update' skip the
+#     automatic local branch creation?
+#     Affects: 1.2.*.1, 1.3.*.1, 1.4.*.1, 1.5.*.1,
+#              2.2.*.1, 2.3.*.1, 2.4.*.1, 2.5.*.1,
+#              3.2.1.1, 3.3.1.1, 3.4.1.1, 3.5.1.1
+#
+# D5: When in merge/rebase-mode, and 'submodule update' actually ends up doing
+#     a merge/rebase, that will happen on the current branch (or detached HEAD)
+#     and NOT on the configured (or default) .branch. Is this OK? Should we
+#     abort (or at least warn) instead? (In general, .branch seems only to
+#     affect the submodule's HEAD when the submodule is first cloned.)
+#     (This discussion point is related to D3 and D6)
+#     Affects: 1.3.1.3, 1.3.1.5, 1.3.1.7, 1.3.2.>=2,
+#              1.4.1.3, 1.4.1.5, 1.4.1.7, 1.4.2.>=2,
+#              2.3.1.3, 2.3.1.5, 2.3.1.7, 2.3.2.2, 2.3.2.4, 2.3.2.6,
+#              2.4.1.3, 2.4.1.5, 2.4.1.7, 2.4.2.2, 2.4.2.4, 2.4.2.6
+#              3.3.1.3, 3.3.1.5, 3.3.1.7
+#              3.4.1.3, 3.4.1.5, 3.4.1.7
+#
+# D6: The meaning of submodule.<name>.branch is initially confusing, as it does
+#     not really concern the submodule's local branch (except as a naming hint
+#     when the submodule is first cloned). Instead, submodule.<name>.branch is
+#     really about which branch in the _upstream_ submodule (as defined by
+#     submodule.<name>.url, or by the submodule's remote.origin.url?) that we
+#     want to integrate with. This is probably the more useful setting, and it
+#     becomes obviously correct after (re-)reading gitmodules(5) and
+#     git-config(1). However, from just reading the "update" section in
+#     git-submodule(1) (or not even that), things are not so clear-cut. Would
+#     submodule.<name>.upstream (or .remote-branch, or similar) be a better
+#     name for this?
+#
+# D7: What to do when .branch refers to a branch that is missing from upstream?
+#     Currently, when trying to clone, the clone fails (which causes 'git
+#     submodule update --remote' to fail), but leaves the submodule in an
+#     uninitialized state (there is a .git, but the work tree is missing).
+#     This is probably not the behavior we want...
+#     Affects: pre, 3.2.2.1, 3.3.2.1, 3.4.2.1, 3.5.2.1
+
+# First, we need to setup the environment in which the test cases are run.
+# This consists of an upstream super-repo containing a single submodule.
+# The submodule commit graph looks like this:
+#
+#   $root_commit --->  $old_commit ---> $new_commit  <- master (HEAD) # T1
+#                \          ^- (superproject's gitlink points here)
+#                 --> $foo_commit  <- foo
+#
+# Each test case then starts by cloning upstream_super -> super and setting up
+# its submodule + configuration according to the current test case. It then
+# runs "git submodule update" (with or without --remote) and verifies the
+# expected results.
+
+test_expect_success 'preliminaries: setup upstream super and sub' '
+	git init upstream_sub &&
+	(cd upstream_sub &&
+	 test_commit root_commit &&
+	 test_commit foo_commit &&
+	 git branch foo &&
+	 git reset --hard HEAD^ &&
+#	 git branch -m default &&  # T1
+	 test_commit old_commit
+	) &&
+	git init upstream_super &&
+	(cd upstream_super &&
+	 git submodule add ../upstream_sub sub &&
+	 test_tick &&
+	 git commit -m "Add sub"
+	) &&
+	(cd upstream_sub &&
+	 test_commit new_commit
+	)
+'
+
+# The following commit IDs are used in various test cases
+root_commit=$(git -C upstream_sub rev-parse --verify -q root_commit)
+foo_commit=$(git -C upstream_sub rev-parse --verify -q foo_commit)
+old_commit=$(git -C upstream_sub rev-parse --verify -q old_commit)
+new_commit=$(git -C upstream_sub rev-parse --verify -q new_commit)
+
+fail()
+{
+	echo "$@"
+	false
+}
+
+# Verify that the path in $1 contains a cloned git repo
+verify_is_cloned()
+{
+	test -e "$1/.git" ||
+		fail "Failed to find cloned repo at '$1'"
+}
+
+# Verify that commit $2 in repo $1 has parents $3, $4, ... (in the given order).
+verify_parents()
+{
+	repo=$1; shift
+	commit=$1; shift
+	expect_p=$@
+	actual_p=$(git --git-dir="$repo/.git" log --format=%P -1 "$commit")
+	test "$expect_p" = "$actual_p" ||
+		fail "Expected $commit parents '$expect_p' != '$actual_p'"
+}
+
+# Verify that HEAD in repo $1 points to commit $2.
+# If $2 is of the form 'parents.<SHA1>[.<SHA1>...]', then check that HEAD
+# currently points to a commit whose parents are the given SHA1s (in order).
+verify_head()
+{
+	head=$(git --git-dir="$1/.git" rev-parse -q HEAD)
+	case "$2" in
+	parents.*)
+		parents=$(echo "$2" | sed -e 's/^parents\.//' -e 's/\./ /g')
+		verify_parents "$1" "$head" $parents ||
+			fail "Failed to verify parents of HEAD in '$1'"
+		;;
+	*)
+		test "$2" = "$head" ||
+			fail "Expected HEAD in '$1' to be '$2', but is '$head'"
+	esac
+}
+
+# Verify that the repo in $1 is currently checked out on branch $2.
+# If $2 is "detached", verify that $1'a HEAD is in fact detached.
+verify_branch()
+{
+	expect=$2
+	if test "$expect" = "detached"
+	then
+		expect=
+	fi
+	actual=$(git --git-dir="$1/.git" symbolic-ref --short -q HEAD)
+	test "$expect" = "$actual" ||
+		fail "Expected branch in '$1' to be '$expect', but is '$actual'"
+}
+
+# Clone upstream_super to super, and run "git submodule init"
+setup_super()
+{
+	rm -rf super &&
+	git clone upstream_super super &&
+	(cd super &&
+	 git submodule init &&
+	 test_must_fail verify_is_cloned sub &&
+	 test "$(git rev-parse -q HEAD:sub)" = "$old_commit"
+	)
+}
+
+# Setup submodule.sub.branch == $1
+# If $1 == "unset", ensure submodule.sub.branch is unset
+setup_sub_branch()
+{
+	if test "$1" = "unset"
+	then
+		git config --unset-all "submodule.sub.branch"
+		test_must_fail git config "submodule.sub.branch" ||
+			error "Failed to unset submodule.sub.branch"
+	else
+		git config "submodule.sub.branch" "$1"
+		actual=$(git config "submodule.sub.branch")
+		test "$actual" = "$1" ||
+			error "Failed to set submodule.sub.branch to '$1'"
+	fi
+}
+
+# Setup submodule.sub.update == $1
+setup_sub_update()
+{
+	git config "submodule.sub.update" "$1"
+	actual=$(git config "submodule.sub.update")
+	test "$actual" = "$1" ||
+		error "Failed to set submodule.sub.update to '$1'"
+}
+
+# Setup the state of the sub submodule according to $1, which is one of:
+#  - "uncloned" - sub is an empty dir.
+#  - "detach" - sub is detached at the commit in $2.
+#  - * - sub is checked out on branch named in $1, at the commit in $2.
+setup_sub_state()
+{
+	case "$1" in
+	uncloned)
+		test_must_fail verify_is_cloned sub ||
+			error "Failed to verify uncloned sub"
+		;;
+	detach)
+		git submodule update --checkout sub &&
+		(cd sub &&
+		 git checkout "$2"
+		) &&
+		verify_is_cloned sub &&
+		verify_branch sub detached &&
+		verify_head sub "$2" ||
+			error "Failed to detach sub at '$2'"
+		;;
+	*)
+		git submodule update --checkout sub &&
+		(cd sub &&
+		 git checkout -b "$1" "$2"
+		) &&
+		verify_is_cloned sub &&
+		verify_branch sub "$1" &&
+		verify_head sub "$2" ||
+			error "Failed to attach sub to '$1' at '$2'"
+	esac
+}
+
+# Verify the state of the sub submodule according to $1, which is one of:
+#  - "uncloned" - sub is an empty dir.
+#  - "detach" - sub is detached at the commit in $2.
+#  - * - sub is checked out on branch named in $1, at the commit in $2.
+# If $2 is of the form 'parents.<SHA1>[.<SHA1>...]', then check that HEAD
+# currently points to a commit whose parents are the given SHA1s (in order).
+verify_sub_state()
+{
+	case "$1" in
+	uncloned)
+		test_must_fail verify_is_cloned sub ||
+			fail "Failed to verify uncloned sub"
+		;;
+	detach)
+		verify_is_cloned sub &&
+		verify_branch sub detached &&
+		verify_head sub "$2" ||
+			fail "Failed to verify detached sub at '$2'"
+		;;
+	*)
+		verify_is_cloned sub &&
+		verify_branch sub "$1" &&
+		verify_head sub "$2" ||
+			fail "Failed to verify attached sub at '$1' -> '$2'"
+	esac
+}
+
+verify_sub_patch_id()
+{
+	p1=$(git --git-dir=sub/.git show $1 | git patch-id | cut -d' ' -f1)
+	p2=$(git --git-dir=sub/.git show $2 | git patch-id | cut -d' ' -f1)
+	test "$p1" = "$p2" ||
+		fail "'$1' and '$2' has different patch-ids ('$p1' != '$p2')"
+}
+
+# 1.1.* - .branch is unset, .update == none
+
+test_expect_success '1.1.1.1 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update none &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state uncloned
+	)
+'
+
+test_expect_success '1.1.1.2 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_success '1.1.1.3 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state detach $foo_commit
+	)
+'
+
+test_expect_success '1.1.1.4 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state foo $old_commit
+	)
+'
+
+test_expect_success '1.1.1.5 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state foo $foo_commit
+	)
+'
+
+test_expect_success '1.1.1.6 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state bar $old_commit
+	)
+'
+
+test_expect_success '1.1.1.7 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state bar $foo_commit
+	)
+'
+
+test_expect_success '1.1.2.1 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update none &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state uncloned
+	)
+'
+
+test_expect_success '1.1.2.2 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_success '1.1.2.3 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $foo_commit
+	)
+'
+
+test_expect_success '1.1.2.4 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state foo $old_commit
+	)
+'
+
+test_expect_success '1.1.2.5 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state foo $foo_commit
+	)
+'
+
+test_expect_success '1.1.2.6 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state bar $old_commit
+	)
+'
+
+test_expect_success '1.1.2.7 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state bar $foo_commit
+	)
+'
+
+# 1.2.* - .branch is unset, .update == checkout
+
+test_expect_success '1.2.1.1 - clone, detach @ $old_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit # D4
+	)
+'
+
+test_expect_success '1.2.1.2 - already @ $old_commit -> keep detached' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_success '1.2.1.3 - detach @ $old_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_success '1.2.1.4 - already @ $old_commit -> keep attached' ' # D1
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state foo $old_commit
+	)
+'
+
+test_expect_success '1.2.1.5 - detach @ $old_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_success '1.2.1.6 - already @ $old_commit -> keep attached' ' # D1
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state bar $old_commit
+	)
+'
+
+test_expect_success '1.2.1.7 - detach @ $old_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_success '1.2.2.1 - clone, detach @ $new_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $new_commit # D4
+	)
+'
+
+test_expect_success '1.2.2.2 - detach @ $new_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $new_commit
+	)
+'
+
+test_expect_success '1.2.2.3 - detach @ $new_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $new_commit
+	)
+'
+
+test_expect_success '1.2.2.4 - detach @ $new_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $new_commit
+	)
+'
+
+test_expect_success '1.2.2.5 - detach @ $new_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $new_commit
+	)
+'
+
+test_expect_success '1.2.2.6 - detach @ $new_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $new_commit
+	)
+'
+
+test_expect_success '1.2.2.7 - detach @ $new_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $new_commit
+	)
+'
+
+# 1.3.* - .branch is unset, .update == merge # D2
+
+test_expect_success '1.3.1.1 - clone, create branch named from origin/HEAD @ $old_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update merge &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit # T1, D4, FIXME: s/detach/master/?
+	)
+'
+
+test_expect_success '1.3.1.2 - already at $old_commit, remain detached' ' # D3
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_success '1.3.1.3 - merge $old_commit -> $foo_commit, remain detached' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state detach parents.$foo_commit.$old_commit
+	)
+'
+
+test_expect_success '1.3.1.4 - already at $old_commit, remain attached to foo' ' # D3
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state foo $old_commit
+	)
+'
+
+test_expect_success '1.3.1.5 - merge $old_commit -> $foo_commit, remain attached to foo' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state foo parents.$foo_commit.$old_commit
+	)
+'
+
+test_expect_success '1.3.1.6 - already at $old_commit, remain attached to bar' ' # D3
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state bar $old_commit
+	)
+'
+
+test_expect_success '1.3.1.7 - merge $old_commit -> $foo_commit, remain attached to bar' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state bar parents.$foo_commit.$old_commit
+	)
+'
+
+test_expect_success '1.3.2.1 - clone, create branch from origin/HEAD @ $new_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update merge &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $new_commit # T1, D4, FIXME: s/detach/master/?
+	)
+'
+
+test_expect_success '1.3.2.2 - ffwd $old_commit -> $new_commit, remain detached' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $new_commit
+	)
+'
+
+test_expect_success '1.3.2.3 - merge $new_commit -> $foo_commit, remain detached' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state detach parents.$foo_commit.$new_commit
+	)
+'
+
+test_expect_success '1.3.2.4 - ffwd $old_commit -> $new_commit, remain attached to foo' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state foo $new_commit
+	)
+'
+
+test_expect_success '1.3.2.5 - merge $new_commit -> $foo_commit, remain attached to foo' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state foo parents.$foo_commit.$new_commit
+	)
+'
+
+test_expect_success '1.3.2.6 - ffwd $old_commit -> $new_commit, remain attached to bar' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state bar $new_commit
+	)
+'
+
+test_expect_success '1.3.2.7 - merge $new_commit -> $foo_commit, remain attached to bar' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state bar parents.$foo_commit.$new_commit
+	)
+'
+
+# 1.4.* - .branch is unset, .update == rebase # D2
+
+test_expect_success '1.4.1.1 - clone, create branch named from origin/HEAD @ $old_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit # T1, D4, FIXME: s/detach/master/?
+	)
+'
+
+test_expect_success '1.4.1.2 - already at $old_commit, remain detached' ' # D3
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_success '1.4.1.3 - rebase $foo_commit onto $old_commit, remain detached' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state detach parents.$old_commit &&
+	 verify_sub_patch_id HEAD $foo_commit
+	)
+'
+
+test_expect_success '1.4.1.4 - already at $old_commit, remain attached to foo' ' # D3
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state foo $old_commit
+	)
+'
+
+test_expect_success '1.4.1.5 - rebase $foo_commit onto $old_commit, remain attached to foo' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state foo parents.$old_commit &&
+	 verify_sub_patch_id HEAD $foo_commit
+	)
+'
+
+test_expect_success '1.4.1.6 - already at $old_commit, remain attached to bar' ' # D3
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state bar $old_commit
+	)
+'
+
+test_expect_success '1.4.1.7 - rebase $foo_commit onto $old_commit, remain attached to bar' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state bar parents.$old_commit &&
+	 verify_sub_patch_id HEAD $foo_commit
+	)
+'
+
+test_expect_success '1.4.2.1 - clone, create branch from origin/HEAD @ $new_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $new_commit # T1, D4, FIXME: s/detach/master/?
+	)
+'
+
+test_expect_success '1.4.2.2 - ffwd $old_commit -> $new_commit, remain detached' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $new_commit
+	)
+'
+
+test_expect_success '1.4.2.3 - rebase $foo_commit onto $new_commit, remain detached' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state detach parents.$new_commit &&
+	 verify_sub_patch_id HEAD $foo_commit
+	)
+'
+
+test_expect_success '1.4.2.4 - ffwd $old_commit -> $new_commit, remain attached to foo' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state foo $new_commit
+	)
+'
+
+test_expect_success '1.4.2.5 - rebase $foo_commit onto $new_commit, remain attached to foo' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state foo parents.$new_commit &&
+	 verify_sub_patch_id HEAD $foo_commit
+	)
+'
+
+test_expect_success '1.4.2.6 - ffwd $old_commit -> $new_commit, remain attached to bar' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state bar $new_commit
+	)
+'
+
+test_expect_success '1.4.2.7 - rebase $foo_commit onto $new_commit, remain attached to bar' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state bar parents.$new_commit
+	 verify_sub_patch_id HEAD $foo_commit
+	)
+'
+
+# 1.5.* - .branch is unset, .update == !command
+
+test_expect_success '1.5.1.1 - clone, create branch named from origin/HEAD @ $old_commit. !command is NOT invoked' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update !false &&
+	 setup_sub_branch unset &&
+	 git submodule update && # should not invoke "false"
+	 verify_sub_state detach $old_commit # T1, D4, FIXME: s/detach/master/?
+	)
+'
+
+test_expect_success '1.5.1.2 - already at $old_commit, remain detached. !command is NOT invoked' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update !false &&
+	 setup_sub_branch unset &&
+	 git submodule update && # should not invoke "false"
+	 verify_sub_state detach $old_commit
+	)
+'
+
+cat > test_command.sh <<EOF
+#!/bin/sh
+# Verify: detached @ $foo_commit, and asked to integrate $old_commit
+test "\$(git symbolic-ref --short -q HEAD)" = "" &&
+test "\$(git rev-parse -q --verify HEAD)" = "$foo_commit" &&
+test "\$1" = "$old_commit" &&
+git checkout -b success $root_commit
+EOF
+chmod +x test_command.sh
+
+test_expect_success '1.5.1.3 - !command invoked to integrate $old_commit -> $foo_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update !../../test_command.sh &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state success $root_commit # test_command.sh is happy
+	)
+'
+
+test_expect_success '1.5.1.4 - already at $old_commit, remain attached to foo. !command is NOT invoked' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update !false &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state foo $old_commit
+	)
+'
+
+cat > test_command.sh <<EOF
+#!/bin/sh
+# Verify: attached to foo @ $foo_commit, and asked to integrate $old_commit
+test "\$(git symbolic-ref --short -q HEAD)" = "foo" &&
+test "\$(git rev-parse -q --verify HEAD)" = "$foo_commit" &&
+test "\$1" = "$old_commit" &&
+git checkout -b success $root_commit
+EOF
+chmod +x test_command.sh
+
+test_expect_success '1.5.1.5 - !command invoked to integrate $old_commit -> foo/$foo_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update !../../test_command.sh &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state success $root_commit # test_command.sh is happy
+	)
+'
+
+test_expect_success '1.5.1.6 - already at $old_commit, remain attached to bar. !command is NOT invoked' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update !false &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state bar $old_commit
+	)
+'
+
+cat > test_command.sh <<EOF
+#!/bin/sh
+# Verify: attached to bar @ $foo_commit, and asked to integrate $old_commit
+test "\$(git symbolic-ref --short -q HEAD)" = "bar" &&
+test "\$(git rev-parse -q --verify HEAD)" = "$foo_commit" &&
+test "\$1" = "$old_commit" &&
+git checkout -b success $root_commit
+EOF
+chmod +x test_command.sh
+
+test_expect_success '1.5.1.7 - !command invoked to integrate $old_commit -> bar/$foo_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update !../../test_command.sh &&
+	 setup_sub_branch unset &&
+	 git submodule update &&
+	 verify_sub_state success $root_commit # test_command.sh is happy
+	)
+'
+
+test_expect_success '1.5.2.1 - clone, create branch from origin/HEAD @ $new_commit. !command is NOT invoked' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update !false &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $new_commit # T1, D4, FIXME: s/detach/master/?
+	)
+'
+
+cat > test_command.sh <<EOF
+#!/bin/sh
+# Verify: detached @ $old_commit, and asked to integrate $new_commit
+test "\$(git symbolic-ref --short -q HEAD)" = "" &&
+test "\$(git rev-parse -q --verify HEAD)" = "$old_commit" &&
+test "\$1" = "$new_commit" &&
+git checkout -b success $root_commit
+EOF
+chmod +x test_command.sh
+
+test_expect_success '1.5.2.2 - !command invoked to integrate $new_commit -> $old_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update !../../test_command.sh &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state success $root_commit # test_command.sh is happy
+	)
+'
+
+cat > test_command.sh <<EOF
+#!/bin/sh
+# Verify: detached @ $foo_commit, and asked to integrate $new_commit
+test "\$(git symbolic-ref --short -q HEAD)" = "" &&
+test "\$(git rev-parse -q --verify HEAD)" = "$foo_commit" &&
+test "\$1" = "$new_commit" &&
+git checkout -b success $root_commit
+EOF
+chmod +x test_command.sh
+
+test_expect_success '1.5.2.3 - !command invoked to integrate $new_commit -> $foo_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update !../../test_command.sh &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state success $root_commit # test_command.sh is happy
+	)
+'
+
+cat > test_command.sh <<EOF
+#!/bin/sh
+# Verify: attached to foo @ $old_commit, and asked to integrate $new_commit
+test "\$(git symbolic-ref --short -q HEAD)" = "foo" &&
+test "\$(git rev-parse -q --verify HEAD)" = "$old_commit" &&
+test "\$1" = "$new_commit" &&
+git checkout -b success $root_commit
+EOF
+chmod +x test_command.sh
+
+test_expect_success '1.5.2.4 - !command invoked to integrate $new_commit -> foo/$old_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update !../../test_command.sh &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state success $root_commit # test_command.sh is happy
+	)
+'
+
+cat > test_command.sh <<EOF
+#!/bin/sh
+# Verify: attached to foo @ $foo_commit, and asked to integrate $new_commit
+test "\$(git symbolic-ref --short -q HEAD)" = "foo" &&
+test "\$(git rev-parse -q --verify HEAD)" = "$foo_commit" &&
+test "\$1" = "$new_commit" &&
+git checkout -b success $root_commit
+EOF
+chmod +x test_command.sh
+
+test_expect_success '1.5.2.5 - !command invoked to integrate $new_commit -> foo/$foo_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update !../../test_command.sh &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state success $root_commit # test_command.sh is happy
+	)
+'
+
+cat > test_command.sh <<EOF
+#!/bin/sh
+# Verify: attached to bar @ $old_commit, and asked to integrate $new_commit
+test "\$(git symbolic-ref --short -q HEAD)" = "bar" &&
+test "\$(git rev-parse -q --verify HEAD)" = "$old_commit" &&
+test "\$1" = "$new_commit" &&
+git checkout -b success $root_commit
+EOF
+chmod +x test_command.sh
+
+test_expect_success '1.5.2.6 - !command invoked to integrate $new_commit -> bar/$old_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update !../../test_command.sh &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state success $root_commit # test_command.sh is happy
+	)
+'
+
+cat > test_command.sh <<EOF
+#!/bin/sh
+# Verify: attached to bar @ $foo_commit, and asked to integrate $new_commit
+test "\$(git symbolic-ref --short -q HEAD)" = "bar" &&
+test "\$(git rev-parse -q --verify HEAD)" = "$foo_commit" &&
+test "\$1" = "$new_commit" &&
+git checkout -b success $root_commit
+EOF
+chmod +x test_command.sh
+
+test_expect_success '1.5.2.7 - !command invoked to integrate $new_commit -> bar/$foo_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update !../../test_command.sh &&
+	 setup_sub_branch unset &&
+	 git submodule update --remote &&
+	 verify_sub_state success $root_commit # test_command.sh is happy
+	)
+'
+
+# 2.1.* - .branch == foo (exists upstream), .update == none
+
+test_expect_success '2.1.1.1 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update none &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state uncloned
+	)
+'
+
+test_expect_success '2.1.1.2 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_success '2.1.1.3 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state detach $foo_commit
+	)
+'
+
+test_expect_success '2.1.1.4 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state foo $old_commit
+	)
+'
+
+test_expect_success '2.1.1.5 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state foo $foo_commit
+	)
+'
+
+test_expect_success '2.1.1.6 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state bar $old_commit
+	)
+'
+
+test_expect_success '2.1.1.7 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state bar $foo_commit
+	)
+'
+
+test_expect_success '2.1.2.1 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update none &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state uncloned
+	)
+'
+
+test_expect_success '2.1.2.2 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_success '2.1.2.3 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $foo_commit
+	)
+'
+
+test_expect_success '2.1.2.4 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state foo $old_commit
+	)
+'
+
+test_expect_success '2.1.2.5 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state foo $foo_commit
+	)
+'
+
+test_expect_success '2.1.2.6 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state bar $old_commit
+	)
+'
+
+test_expect_success '2.1.2.7 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state bar $foo_commit
+	)
+'
+
+# 2.2.* - .branch == foo (exists upstream), .update == checkout
+
+test_expect_success '2.2.1.1 - clone, detach @ $old_commit (.branch is ignored)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit # D4
+	)
+'
+
+test_expect_success '2.2.1.2 - already @ $old_commit -> keep detached' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_success '2.2.1.3 - detach @ $old_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_success '2.2.1.4 - already @ $old_commit -> keep attached' ' # D1
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state foo $old_commit
+	)
+'
+
+test_expect_success '2.2.1.5 - detach @ $old_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_success '2.2.1.6 - already @ $old_commit -> keep attached' ' # D1
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state bar $old_commit
+	)
+'
+
+test_expect_success '2.2.1.7 - detach @ $old_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_success '2.2.2.1 - clone, detach @ $foo_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $foo_commit # D4
+	)
+'
+
+test_expect_success '2.2.2.2 - detach @ $foo_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $foo_commit
+	)
+'
+
+test_expect_success '2.2.2.3 - already @ $foo_commit, remain detached' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $foo_commit
+	)
+'
+
+test_expect_success '2.2.2.4 - detach @ $foo_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $foo_commit
+	)
+'
+
+test_expect_success '2.2.2.5 - already @ $foo_commit, remain attached to foo' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state foo $foo_commit
+	)
+'
+
+test_expect_success '2.2.2.6 - detach @ $foo_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $foo_commit
+	)
+'
+
+test_expect_success '2.2.2.7 - already @ $foo_commit, remain attached to bar' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state bar $foo_commit
+	)
+'
+
+# 2.3.* - .branch == foo (exists upstream), .update == merge
+
+test_expect_success '2.3.1.1 - clone, create branch called foo @ $old_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update merge &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit # D4, FIXME: s/detach/foo/?
+	)
+'
+
+test_expect_success '2.3.1.2 - already at $old_commit, remain detached' ' # D3
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_success '2.3.1.3 - merge $old_commit -> $foo_commit, remain detached' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state detach parents.$foo_commit.$old_commit
+	)
+'
+
+test_expect_success '2.3.1.4 - already at $old_commit, remain attached to foo' ' # D3
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state foo $old_commit
+	)
+'
+
+test_expect_success '2.3.1.5 - merge $old_commit -> $foo_commit, remain attached to foo' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state foo parents.$foo_commit.$old_commit
+	)
+'
+
+test_expect_success '2.3.1.6 - already at $old_commit, remain attached to bar' ' # D3
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state bar $old_commit
+	)
+'
+
+test_expect_success '2.3.1.7 - merge $old_commit -> $foo_commit, remain attached to bar' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state bar parents.$foo_commit.$old_commit
+	)
+'
+
+test_expect_success '2.3.2.1 - clone, create branch from origin/foo @ $foo_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update merge &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $foo_commit # D4, FIXME: s/detach/foo/?
+	)
+'
+
+test_expect_success '2.3.2.2 - merge $foo_commit -> $old_commit, remain detached' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state detach parents.$old_commit.$foo_commit
+	)
+'
+
+test_expect_success '2.3.2.3 - already @ $foo_commit, remain detached' ' # D3
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $foo_commit
+	)
+'
+
+test_expect_success '2.3.2.4 - merge $foo_commit -> $old_commit, remain attached to foo' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state foo parents.$old_commit.$foo_commit
+	)
+'
+
+test_expect_success '2.3.2.5 - already @ $foo_commit, remain attached to foo' ' # D3
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state foo $foo_commit
+	)
+'
+
+test_expect_success '2.3.2.6 - merge $foo_commit -> $old_commit, remain attached to bar' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state bar parents.$old_commit.$foo_commit
+	)
+'
+
+test_expect_success '2.3.2.7 - already @ $foo_commit, remain attached to bar' ' # D3
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state bar $foo_commit
+	)
+'
+
+# 2.4.* - .branch == foo (exists upstream), .update == rebase
+
+test_expect_success '2.4.1.1 - clone, create branch called foo @ $old_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit # D4, FIXME: s/detach/foo/?
+	)
+'
+
+test_expect_success '2.4.1.2 - already at $old_commit, remain detached' ' # D3
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_success '2.4.1.3 - rebase $foo_commit onto $old_commit, remain detached' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state detach parents.$old_commit &&
+	 verify_sub_patch_id HEAD $foo_commit
+	)
+'
+
+test_expect_success '2.4.1.4 - already at $old_commit, remain attached to foo' ' # D3
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state foo $old_commit
+	)
+'
+
+test_expect_success '2.4.1.5 - rebase $foo_commit onto $old_commit, remain attached to foo' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state foo parents.$old_commit &&
+	 verify_sub_patch_id HEAD $foo_commit
+	)
+'
+
+test_expect_success '2.4.1.6 - already at $old_commit, remain attached to bar' ' # D3
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state bar $old_commit
+	)
+'
+
+test_expect_success '2.4.1.7 - rebase $foo_commit onto $old_commit, remain attached to bar' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state bar parents.$old_commit &&
+	 verify_sub_patch_id HEAD $foo_commit
+	)
+'
+
+test_expect_success '2.4.2.1 - clone, create branch from origin/foo @ $foo_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $foo_commit # D4, FIXME: s/detach/foo/?
+	)
+'
+
+test_expect_success '2.4.2.2 - rebase $old_commit onto $foo_commit, remain detached' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state detach parents.$foo_commit &&
+	 verify_sub_patch_id HEAD $old_commit
+	)
+'
+
+test_expect_success '2.4.2.3 - already @ $foo_commit, remain detached' ' # D3
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $foo_commit
+	)
+'
+
+test_expect_success '2.4.2.4 - rebase $old_commit onto $foo_commit, remain attached to foo' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state foo parents.$foo_commit &&
+	 verify_sub_patch_id HEAD $old_commit
+	)
+'
+
+test_expect_success '2.4.2.5 - already @ $foo_commit, remain attached to foo' ' # D3
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state foo $foo_commit
+	)
+'
+
+test_expect_success '2.4.2.6 - rebase $old_commit onto $foo_commit, remain attached to bar' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state bar parents.$foo_commit &&
+	 verify_sub_patch_id HEAD $old_commit
+	)
+'
+
+test_expect_success '2.4.2.7 - already @ $foo_commit, remain attached to bar' ' # D3
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state bar $foo_commit
+	)
+'
+
+# 2.5.* - .branch == foo (exists upstream), .update == !command
+
+test_expect_success '2.5.1.1 - clone, create branch called foo @ $old_commit. !command is NOT invoked' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update !false &&
+	 setup_sub_branch foo &&
+	 git submodule update && # should not invoke "false"
+	 verify_sub_state detach $old_commit # D4, FIXME: s/detach/foo/?
+	)
+'
+
+test_expect_success '2.5.1.2 - already at $old_commit, remain detached. !command is NOT invoked' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update !false &&
+	 setup_sub_branch foo &&
+	 git submodule update && # should not invoke "false"
+	 verify_sub_state detach $old_commit
+	)
+'
+
+cat > test_command.sh <<EOF
+#!/bin/sh
+# Verify: detached @ $foo_commit, and asked to integrate $old_commit
+test "\$(git symbolic-ref --short -q HEAD)" = "" &&
+test "\$(git rev-parse -q --verify HEAD)" = "$foo_commit" &&
+test "\$1" = "$old_commit" &&
+git checkout -b success $root_commit
+EOF
+chmod +x test_command.sh
+
+test_expect_success '2.5.1.3 - !command invoked to integrate $old_commit -> $foo_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update !../../test_command.sh &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state success $root_commit # test_command.sh is happy
+	)
+'
+
+test_expect_success '2.5.1.4 - already at $old_commit, remain attached to foo. !command is NOT invoked' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update !false &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state foo $old_commit
+	)
+'
+
+cat > test_command.sh <<EOF
+#!/bin/sh
+# Verify: attached to foo @ $foo_commit, and asked to integrate $old_commit
+test "\$(git symbolic-ref --short -q HEAD)" = "foo" &&
+test "\$(git rev-parse -q --verify HEAD)" = "$foo_commit" &&
+test "\$1" = "$old_commit" &&
+git checkout -b success $root_commit
+EOF
+chmod +x test_command.sh
+
+test_expect_success '2.5.1.5 - !command invoked to integrate $old_commit -> foo/$foo_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update !../../test_command.sh &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state success $root_commit # test_command.sh is happy
+	)
+'
+
+test_expect_success '2.5.1.6 - already at $old_commit, remain attached to bar. !command is NOT invoked' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update !false &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state bar $old_commit
+	)
+'
+
+cat > test_command.sh <<EOF
+#!/bin/sh
+# Verify: attached to bar @ $foo_commit, and asked to integrate $old_commit
+test "\$(git symbolic-ref --short -q HEAD)" = "bar" &&
+test "\$(git rev-parse -q --verify HEAD)" = "$foo_commit" &&
+test "\$1" = "$old_commit" &&
+git checkout -b success $root_commit
+EOF
+chmod +x test_command.sh
+
+test_expect_success '2.5.1.7 - !command invoked to integrate $old_commit -> bar/$foo_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update !../../test_command.sh &&
+	 setup_sub_branch foo &&
+	 git submodule update &&
+	 verify_sub_state success $root_commit # test_command.sh is happy
+	)
+'
+
+test_expect_success '2.5.2.1 - clone, create branch from origin/foo @ $foo_commit. !command is NOT invoked' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update !false &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $foo_commit # D4, FIXME: s/detach/foo/?
+	)
+'
+
+cat > test_command.sh <<EOF
+#!/bin/sh
+# Verify: detached @ $old_commit, and asked to integrate $foo_commit
+test "\$(git symbolic-ref --short -q HEAD)" = "" &&
+test "\$(git rev-parse -q --verify HEAD)" = "$old_commit" &&
+test "\$1" = "$foo_commit" &&
+git checkout -b success $root_commit
+EOF
+chmod +x test_command.sh
+
+test_expect_success '2.5.2.2 - !command invoked to integrate $foo_commit -> $old_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update !../../test_command.sh &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state success $root_commit # test_command.sh is happy
+	)
+'
+
+test_expect_success '2.5.2.3 - already at $foo_commit, remain detached. !command is NOT invoked' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update !false &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $foo_commit
+	)
+'
+
+cat > test_command.sh <<EOF
+#!/bin/sh
+# Verify: attached to foo @ $old_commit, and asked to integrate $foo_commit
+test "\$(git symbolic-ref --short -q HEAD)" = "foo" &&
+test "\$(git rev-parse -q --verify HEAD)" = "$old_commit" &&
+test "\$1" = "$foo_commit" &&
+git checkout -b success $root_commit
+EOF
+chmod +x test_command.sh
+
+test_expect_success '2.5.2.4 - !command invoked to integrate $foo_commit -> foo/$old_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update !../../test_command.sh &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state success $root_commit # test_command.sh is happy
+	)
+'
+
+test_expect_success '2.5.2.5 - already at $foo_commit, remain attached to foo. !command is NOT invoked' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update !false &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state foo $foo_commit
+	)
+'
+
+cat > test_command.sh <<EOF
+#!/bin/sh
+# Verify: attached to bar @ $old_commit, and asked to integrate $foo_commit
+test "\$(git symbolic-ref --short -q HEAD)" = "bar" &&
+test "\$(git rev-parse -q --verify HEAD)" = "$old_commit" &&
+test "\$1" = "$foo_commit" &&
+git checkout -b success $root_commit
+EOF
+chmod +x test_command.sh
+
+test_expect_success '2.5.2.6 - !command invoked to integrate $foo_commit -> bar/$old_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update !../../test_command.sh &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state success $root_commit # test_command.sh is happy
+	)
+'
+
+test_expect_success '2.5.2.7 - already at $foo_commit, remain attached to bar. !command is NOT invoked' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update !false &&
+	 setup_sub_branch foo &&
+	 git submodule update --remote &&
+	 verify_sub_state bar $foo_commit
+	)
+'
+
+# 3.1.* - .branch == bar (MISSING upstream), .update == none
+
+test_expect_success '3.1.1.1 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update none &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state uncloned
+	)
+'
+
+test_expect_success '3.1.1.2 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_success '3.1.1.3 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state detach $foo_commit
+	)
+'
+
+test_expect_success '3.1.1.4 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state foo $old_commit
+	)
+'
+
+test_expect_success '3.1.1.5 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state foo $foo_commit
+	)
+'
+
+test_expect_success '3.1.1.6 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state bar $old_commit
+	)
+'
+
+test_expect_success '3.1.1.7 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state bar $foo_commit
+	)
+'
+
+test_expect_success '3.1.2.1 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update none &&
+	 setup_sub_branch bar &&
+	 git submodule update --remote &&
+	 verify_sub_state uncloned
+	)
+'
+
+test_expect_success '3.1.2.2 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch bar &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_success '3.1.2.3 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch bar &&
+	 git submodule update --remote &&
+	 verify_sub_state detach $foo_commit
+	)
+'
+
+test_expect_success '3.1.2.4 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch bar &&
+	 git submodule update --remote &&
+	 verify_sub_state foo $old_commit
+	)
+'
+
+test_expect_success '3.1.2.5 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch bar &&
+	 git submodule update --remote &&
+	 verify_sub_state foo $foo_commit
+	)
+'
+
+test_expect_success '3.1.2.6 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch bar &&
+	 git submodule update --remote &&
+	 verify_sub_state bar $old_commit
+	)
+'
+
+test_expect_success '3.1.2.7 - do nothing (.update == none)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update none &&
+	 setup_sub_branch bar &&
+	 git submodule update --remote &&
+	 verify_sub_state bar $foo_commit
+	)
+'
+
+# 3.2.* - .branch == bar (MISSING upstream), .update == checkout
+
+test_expect_success '3.2.1.1 - clone, detach @ $old_commit (.branch is ignored)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit # D4
+	)
+'
+
+test_expect_success '3.2.1.2 - already @ $old_commit -> keep detached' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_success '3.2.1.3 - detach @ $old_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_success '3.2.1.4 - already @ $old_commit -> keep attached' ' # D1
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state foo $old_commit
+	)
+'
+
+test_expect_success '3.2.1.5 - detach @ $old_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_success '3.2.1.6 - already @ $old_commit -> keep attached' ' # D1
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state bar $old_commit
+	)
+'
+
+test_expect_success '3.2.1.7 - detach @ $old_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_failure '3.2.2.1 - fail to clone (remote branch bar missing), leave uncloned' ' # T3, D7
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state uncloned
+	)
+'
+
+test_expect_success '3.2.2.2 - fail (remote branch bar missing)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_success '3.2.2.3 - fail (remote branch bar missing)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state detach $foo_commit
+	)
+'
+
+test_expect_success '3.2.2.4 - fail (remote branch bar missing)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state foo $old_commit
+	)
+'
+
+test_expect_success '3.2.2.5 - fail (remote branch bar missing)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state foo $foo_commit
+	)
+'
+
+test_expect_success '3.2.2.6 - fail (remote branch bar missing)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state bar $old_commit
+	)
+'
+
+test_expect_success '3.2.2.7 - fail (remote branch bar missing)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update checkout &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state bar $foo_commit
+	)
+'
+
+# 3.3.* - .branch == bar (MISSING upstream), .update == merge
+
+test_expect_success '3.3.1.1 - clone, create branch called bar @ $old_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update merge &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit # D4, FIXME: s/detach/bar/?
+	)
+'
+
+test_expect_success '3.3.1.2 - already at $old_commit, remain detached' ' # D3
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_success '3.3.1.3 - merge $old_commit -> $foo_commit, remain detached' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state detach parents.$foo_commit.$old_commit
+	)
+'
+
+test_expect_success '3.3.1.4 - already at $old_commit, remain attached to foo' ' # D3
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state foo $old_commit
+	)
+'
+
+test_expect_success '3.3.1.5 - merge $old_commit -> $foo_commit, remain attached to foo' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state foo parents.$foo_commit.$old_commit
+	)
+'
+
+test_expect_success '3.3.1.6 - already at $old_commit, remain attached to bar' ' # D3
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state bar $old_commit
+	)
+'
+
+test_expect_success '3.3.1.7 - merge $old_commit -> $foo_commit, remain attached to bar' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state bar parents.$foo_commit.$old_commit
+	)
+'
+
+test_expect_failure '3.3.2.1 - fail to clone (remote branch bar missing), leave uncloned' ' # T3, D7
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update merge &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state uncloned
+	)
+'
+
+test_expect_success '3.3.2.2 - fail (remote branch bar missing)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_success '3.3.2.3 - fail (remote branch bar missing)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state detach $foo_commit
+	)
+'
+
+test_expect_success '3.3.2.4 - fail (remote branch bar missing)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state foo $old_commit
+	)
+'
+
+test_expect_success '3.3.2.5 - fail (remote branch bar missing)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state foo $foo_commit
+	)
+'
+
+test_expect_success '3.3.2.6 - fail (remote branch bar missing)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state bar $old_commit
+	)
+'
+
+test_expect_success '3.3.2.7 - fail (remote branch bar missing)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update merge &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state bar $foo_commit
+	)
+'
+
+# 3.4.* - .branch == bar (MISSING upstream), .update == rebase
+
+test_expect_success '3.4.1.1 - clone, create branch called bar @ $old_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit # D4, FIXME: s/detach/bar/?
+	)
+'
+
+test_expect_success '3.4.1.2 - already at $old_commit, remain detached' ' # D3
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_success '3.4.1.3 - rebase $foo_commit onto $old_commit, remain detached' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state detach parents.$old_commit &&
+	 verify_sub_patch_id HEAD $foo_commit
+	)
+'
+
+test_expect_success '3.4.1.4 - already at $old_commit, remain attached to foo' ' # D3
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state foo $old_commit
+	)
+'
+
+test_expect_success '3.4.1.5 - rebase $foo_commit onto $old_commit, remain attached to foo' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state foo parents.$old_commit &&
+	 verify_sub_patch_id HEAD $foo_commit
+	)
+'
+
+test_expect_success '3.4.1.6 - already at $old_commit, remain attached to bar' ' # D3
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state bar $old_commit
+	)
+'
+
+test_expect_success '3.4.1.7 - rebase $foo_commit onto $old_commit, remain attached to bar' ' # D5
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state bar parents.$old_commit &&
+	 verify_sub_patch_id HEAD $foo_commit
+	)
+'
+
+test_expect_failure '3.4.2.1 - fail to clone (remote branch bar missing), leave uncloned' ' # T3, D7
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state uncloned
+	)
+'
+
+test_expect_success '3.4.2.2 - fail (remote branch bar missing)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_success '3.4.2.3 - fail (remote branch bar missing)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state detach $foo_commit
+	)
+'
+
+test_expect_success '3.4.2.4 - fail (remote branch bar missing)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state foo $old_commit
+	)
+'
+
+test_expect_success '3.4.2.5 - fail (remote branch bar missing)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state foo $foo_commit
+	)
+'
+
+test_expect_success '3.4.2.6 - fail (remote branch bar missing)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state bar $old_commit
+	)
+'
+
+test_expect_success '3.4.2.7 - fail (remote branch bar missing)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update rebase &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state bar $foo_commit
+	)
+'
+
+# 3.5.* - .branch == bar (MISSING upstream), .update == !command
+
+test_expect_success '3.5.1.1 - clone, create branch called bat @ $old_commit. !command is NOT invoked' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update !false &&
+	 setup_sub_branch bar &&
+	 git submodule update && # should not invoke "false"
+	 verify_sub_state detach $old_commit # D4, FIXME: s/detach/bar/?
+	)
+'
+
+test_expect_success '3.5.1.2 - already at $old_commit, remain detached. !command is NOT invoked' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update !false &&
+	 setup_sub_branch bar &&
+	 git submodule update && # should not invoke "false"
+	 verify_sub_state detach $old_commit
+	)
+'
+
+cat > test_command.sh <<EOF
+#!/bin/sh
+# Verify: detached @ $foo_commit, and asked to integrate $old_commit
+test "\$(git symbolic-ref --short -q HEAD)" = "" &&
+test "\$(git rev-parse -q --verify HEAD)" = "$foo_commit" &&
+test "\$1" = "$old_commit" &&
+git checkout -b success $root_commit
+EOF
+chmod +x test_command.sh
+
+test_expect_success '3.5.1.3 - !command invoked to integrate $old_commit -> $foo_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update !../../test_command.sh &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state success $root_commit # test_command.sh is happy
+	)
+'
+
+test_expect_success '3.5.1.4 - already at $old_commit, remain attached to foo. !command is NOT invoked' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update !false &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state foo $old_commit
+	)
+'
+
+cat > test_command.sh <<EOF
+#!/bin/sh
+# Verify: attached to foo @ $foo_commit, and asked to integrate $old_commit
+test "\$(git symbolic-ref --short -q HEAD)" = "foo" &&
+test "\$(git rev-parse -q --verify HEAD)" = "$foo_commit" &&
+test "\$1" = "$old_commit" &&
+git checkout -b success $root_commit
+EOF
+chmod +x test_command.sh
+
+test_expect_success '3.5.1.5 - !command invoked to integrate $old_commit -> foo/$foo_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update !../../test_command.sh &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state success $root_commit # test_command.sh is happy
+	)
+'
+
+test_expect_success '3.5.1.6 - already at $old_commit, remain attached to bar. !command is NOT invoked' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update !false &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state bar $old_commit
+	)
+'
+
+cat > test_command.sh <<EOF
+#!/bin/sh
+# Verify: attached to bar @ $foo_commit, and asked to integrate $old_commit
+test "\$(git symbolic-ref --short -q HEAD)" = "bar" &&
+test "\$(git rev-parse -q --verify HEAD)" = "$foo_commit" &&
+test "\$1" = "$old_commit" &&
+git checkout -b success $root_commit
+EOF
+chmod +x test_command.sh
+
+test_expect_success '3.5.1.7 - !command invoked to integrate $old_commit -> bar/$foo_commit' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update !../../test_command.sh &&
+	 setup_sub_branch bar &&
+	 git submodule update &&
+	 verify_sub_state success $root_commit # test_command.sh is happy
+	)
+'
+
+test_expect_failure '3.5.2.1 - fail to clone (remote branch bar missing), leave uncloned' ' # T3, D7
+	setup_super &&
+	(cd super &&
+	 setup_sub_state uncloned &&
+	 setup_sub_update !false &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state uncloned
+	)
+'
+
+test_expect_success '3.5.2.2 - fail (remote branch bar missing, !command not invoked)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $old_commit &&
+	 setup_sub_update !false &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state detach $old_commit
+	)
+'
+
+test_expect_success '3.5.2.3 - fail (remote branch bar missing, !command not invoked)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state detach $foo_commit &&
+	 setup_sub_update !false &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state detach $foo_commit
+	)
+'
+
+test_expect_success '3.5.2.4 - fail (remote branch bar missing, !command not invoked)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $old_commit &&
+	 setup_sub_update !false &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state foo $old_commit
+	)
+'
+
+test_expect_success '3.5.2.5 - fail (remote branch bar missing, !command not invoked)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state foo $foo_commit &&
+	 setup_sub_update !false &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state foo $foo_commit
+	)
+'
+
+test_expect_success '3.5.2.6 - fail (remote branch bar missing, !command not invoked)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $old_commit &&
+	 setup_sub_update !false &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state bar $old_commit
+	)
+'
+
+test_expect_success '3.5.2.7 - fail (remote branch bar missing, !command not invoked)' '
+	setup_super &&
+	(cd super &&
+	 setup_sub_state bar $foo_commit &&
+	 setup_sub_update !false &&
+	 setup_sub_branch bar &&
+	 test_must_fail git submodule update --remote &&
+	 verify_sub_state bar $foo_commit
+	)
+'
+
+test_done