branch: name detached HEAD analogous to statusmg/detached-head-report

"git status" carefully names a detached HEAD "at" resp. "from" a rev or
ref depending on whether the detached HEAD has moved since. "git branch"
always uses "from", which can be confusing, because a status-aware user
would interpret this as moved detached HEAD.

Make "git branch" use the same logic and wording.

Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 38 insertions, 1 deletions

diff --git a/t/t3203-branch-output.sh b/t/t3203-branch-output.sh
index ba4f98e800..f51d0f3cad 100755
--- a/t/t3203-branch-output.sh
+++ b/t/t3203-branch-output.sh
@@ -96,7 +96,7 @@ test_expect_success 'git branch -v pattern does not show branch summaries' '
 
 test_expect_success 'git branch shows detached HEAD properly' '
 	cat >expect <<EOF &&
-* (detached from $(git rev-parse --short HEAD^0))
+* (HEAD detached at $(git rev-parse --short HEAD^0))
   branch-one
   branch-two
   master
@@ -106,4 +106,41 @@ EOF
 	test_i18ncmp expect actual
 '
 
+test_expect_success 'git branch shows detached HEAD properly after moving' '
+	cat >expect <<EOF &&
+* (HEAD detached from $(git rev-parse --short HEAD))
+  branch-one
+  branch-two
+  master
+EOF
+	git reset --hard HEAD^1 &&
+	git branch >actual &&
+	test_i18ncmp expect actual
+'
+
+test_expect_success 'git branch shows detached HEAD properly from tag' '
+	cat >expect <<EOF &&
+* (HEAD detached at fromtag)
+  branch-one
+  branch-two
+  master
+EOF
+	git tag fromtag master &&
+	git checkout fromtag &&
+	git branch >actual &&
+	test_i18ncmp expect actual
+'
+
+test_expect_success 'git branch shows detached HEAD properly after moving from tag' '
+	cat >expect <<EOF &&
+* (HEAD detached from fromtag)
+  branch-one
+  branch-two
+  master
+EOF
+	git reset --hard HEAD^1 &&
+	git branch >actual &&
+	test_i18ncmp expect actual
+'
+
 test_done