Merge branch 'js/diff-verbose-submodule'

* js/diff-verbose-submodule:
  add tests for git diff --submodule
  Add the --submodule option to the diff option family

7 files changed, 411 insertions, 0 deletions

diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index 9276faeb11..e26b84706f 100644
--- a/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt
@@ -87,6 +87,13 @@ endif::git-format-patch[]
 	Show only names and status of changed files. See the description
 	of the `--diff-filter` option on what the status letters mean.
 
+--submodule[=<format>]::
+	Chose the output format for submodule differences. <format> can be one of
+	'short' and 'log'. 'short' just shows pairs of commit names, this format
+	is used when this option is not given. 'log' is the default value for this
+	option and lists the commits in that commit range like the 'summary'
+	option of linkgit:git-submodule[1] does.
+
 --color::
 	Show colored diff.
 
diff --git a/Makefile b/Makefile
index 9c5d299f4d..15ea32d394 100644
--- a/Makefile
+++ b/Makefile
@@ -456,6 +456,7 @@ LIB_H += sideband.h
 LIB_H += sigchain.h
 LIB_H += strbuf.h
 LIB_H += string-list.h
+LIB_H += submodule.h
 LIB_H += tag.h
 LIB_H += transport.h
 LIB_H += tree.h
@@ -554,6 +555,7 @@ LIB_OBJS += sideband.o
 LIB_OBJS += sigchain.o
 LIB_OBJS += strbuf.o
 LIB_OBJS += string-list.o
+LIB_OBJS += submodule.o
 LIB_OBJS += symlinks.o
 LIB_OBJS += tag.o
 LIB_OBJS += trace.o
diff --git a/diff.c b/diff.c
index b0c7e616a6..3ad1f8c310 100644
--- a/diff.c
+++ b/diff.c
@@ -13,6 +13,7 @@
 #include "utf8.h"
 #include "userdiff.h"
 #include "sigchain.h"
+#include "submodule.h"
 
 #ifdef NO_FAST_WORKING_DIRECTORY
 #define FAST_WORKING_DIRECTORY 0
@@ -1557,6 +1558,17 @@ static void builtin_diff(const char *name_a,
 	const char *a_prefix, *b_prefix;
 	const char *textconv_one = NULL, *textconv_two = NULL;
 
+	if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
+			(!one->mode || S_ISGITLINK(one->mode)) &&
+			(!two->mode || S_ISGITLINK(two->mode))) {
+		const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
+		const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
+		show_submodule_summary(o->file, one ? one->path : two->path,
+				one->sha1, two->sha1,
+				del, add, reset);
+		return;
+	}
+
 	if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
 		textconv_one = get_textconv(one);
 		textconv_two = get_textconv(two);
@@ -2757,6 +2769,12 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 		DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
 	else if (!strcmp(arg, "--ignore-submodules"))
 		DIFF_OPT_SET(options, IGNORE_SUBMODULES);
+	else if (!strcmp(arg, "--submodule"))
+		DIFF_OPT_SET(options, SUBMODULE_LOG);
+	else if (!prefixcmp(arg, "--submodule=")) {
+		if (!strcmp(arg + 12, "log"))
+			DIFF_OPT_SET(options, SUBMODULE_LOG);
+	}
 
 	/* misc options */
 	else if (!strcmp(arg, "-z"))
diff --git a/diff.h b/diff.h
index 6616877ee5..2740421cfe 100644
--- a/diff.h
+++ b/diff.h
@@ -66,6 +66,9 @@ typedef void (*diff_format_fn_t)(struct diff_queue_struct *q,
 #define DIFF_OPT_DIRSTAT_CUMULATIVE  (1 << 19)
 #define DIFF_OPT_DIRSTAT_BY_FILE     (1 << 20)
 #define DIFF_OPT_ALLOW_TEXTCONV      (1 << 21)
+
+#define DIFF_OPT_SUBMODULE_LOG       (1 << 23)
+
 #define DIFF_OPT_TST(opts, flag)    ((opts)->flags & DIFF_OPT_##flag)
 #define DIFF_OPT_SET(opts, flag)    ((opts)->flags |= DIFF_OPT_##flag)
 #define DIFF_OPT_CLR(opts, flag)    ((opts)->flags &= ~DIFF_OPT_##flag)
diff --git a/submodule.c b/submodule.c
new file mode 100644
index 0000000000..d5fce7a882
--- /dev/null
+++ b/submodule.c
@@ -0,0 +1,113 @@
+#include "cache.h"
+#include "submodule.h"
+#include "dir.h"
+#include "diff.h"
+#include "commit.h"
+#include "revision.h"
+
+int add_submodule_odb(const char *path)
+{
+	struct strbuf objects_directory = STRBUF_INIT;
+	struct alternate_object_database *alt_odb;
+
+	strbuf_addf(&objects_directory, "%s/.git/objects/", path);
+	if (!is_directory(objects_directory.buf))
+		return -1;
+
+	/* avoid adding it twice */
+	for (alt_odb = alt_odb_list; alt_odb; alt_odb = alt_odb->next)
+		if (alt_odb->name - alt_odb->base == objects_directory.len &&
+				!strncmp(alt_odb->base, objects_directory.buf,
+					objects_directory.len))
+			return 0;
+
+	alt_odb = xmalloc(objects_directory.len + 42 + sizeof(*alt_odb));
+	alt_odb->next = alt_odb_list;
+	strcpy(alt_odb->base, objects_directory.buf);
+	alt_odb->name = alt_odb->base + objects_directory.len;
+	alt_odb->name[2] = '/';
+	alt_odb->name[40] = '\0';
+	alt_odb->name[41] = '\0';
+	alt_odb_list = alt_odb;
+	prepare_alt_odb();
+	return 0;
+}
+
+void show_submodule_summary(FILE *f, const char *path,
+		unsigned char one[20], unsigned char two[20],
+		const char *del, const char *add, const char *reset)
+{
+	struct rev_info rev;
+	struct commit *commit, *left = left, *right;
+	struct commit_list *merge_bases, *list;
+	const char *message = NULL;
+	struct strbuf sb = STRBUF_INIT;
+	static const char *format = "  %m %s";
+	int fast_forward = 0, fast_backward = 0;
+
+	if (is_null_sha1(two))
+		message = "(submodule deleted)";
+	else if (add_submodule_odb(path))
+		message = "(not checked out)";
+	else if (is_null_sha1(one))
+		message = "(new submodule)";
+	else if (!(left = lookup_commit_reference(one)) ||
+		 !(right = lookup_commit_reference(two)))
+		message = "(commits not present)";
+
+	if (!message) {
+		init_revisions(&rev, NULL);
+		setup_revisions(0, NULL, &rev, NULL);
+		rev.left_right = 1;
+		rev.first_parent_only = 1;
+		left->object.flags |= SYMMETRIC_LEFT;
+		add_pending_object(&rev, &left->object, path);
+		add_pending_object(&rev, &right->object, path);
+		merge_bases = get_merge_bases(left, right, 1);
+		if (merge_bases) {
+			if (merge_bases->item == left)
+				fast_forward = 1;
+			else if (merge_bases->item == right)
+				fast_backward = 1;
+		}
+		for (list = merge_bases; list; list = list->next) {
+			list->item->object.flags |= UNINTERESTING;
+			add_pending_object(&rev, &list->item->object,
+				sha1_to_hex(list->item->object.sha1));
+		}
+		if (prepare_revision_walk(&rev))
+			message = "(revision walker failed)";
+	}
+
+	strbuf_addf(&sb, "Submodule %s %s..", path,
+			find_unique_abbrev(one, DEFAULT_ABBREV));
+	if (!fast_backward && !fast_forward)
+		strbuf_addch(&sb, '.');
+	strbuf_addf(&sb, "%s", find_unique_abbrev(two, DEFAULT_ABBREV));
+	if (message)
+		strbuf_addf(&sb, " %s\n", message);
+	else
+		strbuf_addf(&sb, "%s:\n", fast_backward ? " (rewind)" : "");
+	fwrite(sb.buf, sb.len, 1, f);
+
+	if (!message) {
+		while ((commit = get_revision(&rev))) {
+			strbuf_setlen(&sb, 0);
+			if (commit->object.flags & SYMMETRIC_LEFT) {
+				if (del)
+					strbuf_addstr(&sb, del);
+			}
+			else if (add)
+				strbuf_addstr(&sb, add);
+			format_commit_message(commit, format, &sb,
+					rev.date_mode);
+			if (reset)
+				strbuf_addstr(&sb, reset);
+			strbuf_addch(&sb, '\n');
+			fprintf(f, "%s", sb.buf);
+		}
+		clear_commit_marks(left, ~0);
+		clear_commit_marks(right, ~0);
+	}
+	strbuf_release(&sb);
+}
diff --git a/submodule.h b/submodule.h
new file mode 100644
index 0000000000..4c0269d679
--- /dev/null
+++ b/submodule.h
@@ -0,0 +1,8 @@
+#ifndef SUBMODULE_H
+#define SUBMODULE_H
+
+void show_submodule_summary(FILE *f, const char *path,
+		unsigned char one[20], unsigned char two[20],
+		const char *del, const char *add, const char *reset);
+
+#endif
diff --git a/t/t4041-diff-submodule.sh b/t/t4041-diff-submodule.sh
new file mode 100755
index 0000000000..5bb4fed3f5
--- /dev/null
+++ b/t/t4041-diff-submodule.sh
@@ -0,0 +1,260 @@
+#!/bin/sh
+#
+# Copyright (c) 2009 Jens Lehmann, based on t7401 by Ping Yin
+#
+
+test_description='Support for verbose submodule differences in git diff
+
+This test tries to verify the sanity of the --submodule option of git diff.
+'
+
+. ./test-lib.sh
+
+add_file () {
+	sm=$1
+	shift
+	owd=$(pwd)
+	cd "$sm"
+	for name; do
+		echo "$name" > "$name" &&
+		git add "$name" &&
+		test_tick &&
+		git commit -m "Add $name"
+	done >/dev/null
+	git rev-parse --verify HEAD | cut -c1-7
+	cd "$owd"
+}
+commit_file () {
+	test_tick &&
+	git commit "$@" -m "Commit $*" >/dev/null
+}
+
+test_create_repo sm1 &&
+add_file . foo >/dev/null
+
+head1=$(add_file sm1 foo1 foo2)
+
+test_expect_success 'added submodule' "
+	git add sm1 &&
+	git diff-index -p --submodule=log HEAD >actual &&
+	diff actual - <<-EOF
+Submodule sm1 0000000...$head1 (new submodule)
+EOF
+"
+
+commit_file sm1 &&
+head2=$(add_file sm1 foo3)
+
+test_expect_success 'modified submodule(forward)' "
+	git diff-index -p --submodule=log HEAD >actual &&
+	diff actual - <<-EOF
+Submodule sm1 $head1..$head2:
+  > Add foo3
+EOF
+"
+
+test_expect_success 'modified submodule(forward)' "
+	git diff --submodule=log >actual &&
+	diff actual - <<-EOF
+Submodule sm1 $head1..$head2:
+  > Add foo3
+EOF
+"
+
+test_expect_success 'modified submodule(forward) --submodule' "
+	git diff --submodule >actual &&
+	diff actual - <<-EOF
+Submodule sm1 $head1..$head2:
+  > Add foo3
+EOF
+"
+
+fullhead1=$(cd sm1; git rev-list --max-count=1 $head1)
+fullhead2=$(cd sm1; git rev-list --max-count=1 $head2)
+test_expect_success 'modified submodule(forward) --submodule=short' "
+	git diff --submodule=short >actual &&
+	diff actual - <<-EOF
+diff --git a/sm1 b/sm1
+index $head1..$head2 160000
+--- a/sm1
++++ b/sm1
+@@ -1 +1 @@
+-Subproject commit $fullhead1
++Subproject commit $fullhead2
+EOF
+"
+
+commit_file sm1 &&
+cd sm1 &&
+git reset --hard HEAD~2 >/dev/null &&
+head3=$(git rev-parse --verify HEAD | cut -c1-7) &&
+cd ..
+
+test_expect_success 'modified submodule(backward)' "
+	git diff-index -p --submodule=log HEAD >actual &&
+	diff actual - <<-EOF
+Submodule sm1 $head2..$head3 (rewind):
+  < Add foo3
+  < Add foo2
+EOF
+"
+
+head4=$(add_file sm1 foo4 foo5) &&
+head4_full=$(GIT_DIR=sm1/.git git rev-parse --verify HEAD)
+test_expect_success 'modified submodule(backward and forward)' "
+	git diff-index -p --submodule=log HEAD >actual &&
+	diff actual - <<-EOF
+Submodule sm1 $head2...$head4:
+  > Add foo5
+  > Add foo4
+  < Add foo3
+  < Add foo2
+EOF
+"
+
+commit_file sm1 &&
+mv sm1 sm1-bak &&
+echo sm1 >sm1 &&
+head5=$(git hash-object sm1 | cut -c1-7) &&
+git add sm1 &&
+rm -f sm1 &&
+mv sm1-bak sm1
+
+test_expect_success 'typechanged submodule(submodule->blob), --cached' "
+	git diff --submodule=log --cached >actual &&
+	diff actual - <<-EOF
+Submodule sm1 41fbea9...0000000 (submodule deleted)
+diff --git a/sm1 b/sm1
+new file mode 100644
+index 0000000..9da5fb8
+--- /dev/null
++++ b/sm1
+@@ -0,0 +1 @@
++sm1
+EOF
+"
+
+test_expect_success 'typechanged submodule(submodule->blob)' "
+	git diff --submodule=log >actual &&
+	diff actual - <<-EOF
+diff --git a/sm1 b/sm1
+deleted file mode 100644
+index 9da5fb8..0000000
+--- a/sm1
++++ /dev/null
+@@ -1 +0,0 @@
+-sm1
+Submodule sm1 0000000...$head4 (new submodule)
+EOF
+"
+
+rm -rf sm1 &&
+git checkout-index sm1
+test_expect_success 'typechanged submodule(submodule->blob)' "
+	git diff-index -p --submodule=log HEAD >actual &&
+	diff actual - <<-EOF
+Submodule sm1 $head4...0000000 (submodule deleted)
+diff --git a/sm1 b/sm1
+new file mode 100644
+index 0000000..$head5
+--- /dev/null
++++ b/sm1
+@@ -0,0 +1 @@
++sm1
+EOF
+"
+
+rm -f sm1 &&
+test_create_repo sm1 &&
+head6=$(add_file sm1 foo6 foo7)
+fullhead6=$(cd sm1; git rev-list --max-count=1 $head6)
+test_expect_success 'nonexistent commit' "
+	git diff-index -p --submodule=log HEAD >actual &&
+	diff actual - <<-EOF
+Submodule sm1 $head4...$head6 (commits not present)
+EOF
+"
+
+commit_file
+test_expect_success 'typechanged submodule(blob->submodule)' "
+	git diff-index -p --submodule=log HEAD >actual &&
+	diff actual - <<-EOF
+diff --git a/sm1 b/sm1
+deleted file mode 100644
+index $head5..0000000
+--- a/sm1
++++ /dev/null
+@@ -1 +0,0 @@
+-sm1
+Submodule sm1 0000000...$head6 (new submodule)
+EOF
+"
+
+commit_file sm1 &&
+rm -rf sm1
+test_expect_success 'deleted submodule' "
+	git diff-index -p --submodule=log HEAD >actual &&
+	diff actual - <<-EOF
+Submodule sm1 $head6...0000000 (submodule deleted)
+EOF
+"
+
+test_create_repo sm2 &&
+head7=$(add_file sm2 foo8 foo9) &&
+git add sm2
+
+test_expect_success 'multiple submodules' "
+	git diff-index -p --submodule=log HEAD >actual &&
+	diff actual - <<-EOF
+Submodule sm1 $head6...0000000 (submodule deleted)
+Submodule sm2 0000000...$head7 (new submodule)
+EOF
+"
+
+test_expect_success 'path filter' "
+	git diff-index -p --submodule=log HEAD sm2 >actual &&
+	diff actual - <<-EOF
+Submodule sm2 0000000...$head7 (new submodule)
+EOF
+"
+
+commit_file sm2
+test_expect_success 'given commit' "
+	git diff-index -p --submodule=log HEAD^ >actual &&
+	diff actual - <<-EOF
+Submodule sm1 $head6...0000000 (submodule deleted)
+Submodule sm2 0000000...$head7 (new submodule)
+EOF
+"
+
+test_expect_success 'given commit --submodule' "
+	git diff-index -p --submodule HEAD^ >actual &&
+	diff actual - <<-EOF
+Submodule sm1 $head6...0000000 (submodule deleted)
+Submodule sm2 0000000...$head7 (new submodule)
+EOF
+"
+
+fullhead7=$(cd sm2; git rev-list --max-count=1 $head7)
+
+test_expect_success 'given commit --submodule=short' "
+	git diff-index -p --submodule=short HEAD^ >actual &&
+	diff actual - <<-EOF
+diff --git a/sm1 b/sm1
+deleted file mode 160000
+index $head6..0000000
+--- a/sm1
++++ /dev/null
+@@ -1 +0,0 @@
+-Subproject commit $fullhead6
+diff --git a/sm2 b/sm2
+new file mode 160000
+index 0000000..$head7
+--- /dev/null
++++ b/sm2
+@@ -0,0 +1 @@
++Subproject commit $fullhead7
+EOF
+"
+
+test_done