Show submodules as modified when they contain a dirty work tree

Until now a submodule only then showed up as modified in the supermodule
when the last commit in the submodule differed from the one in the index
or the diffed against commit of the superproject. A dirty work tree
containing new untracked or modified files in a submodule was
undetectable when looking at it from the superproject.

Now git status and git diff (against the work tree) in the superproject
will also display submodules as modified when they contain untracked or
modified files, even if the compared ref matches the HEAD of the
submodule.

Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Nanako Shiraishi <nanako3@lavabit.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

4 files changed, 124 insertions, 17 deletions

diff --git a/diff-lib.c b/diff-lib.c
index 1c7e652a80..9cdf6daa90 100644
--- a/diff-lib.c
+++ b/diff-lib.c
@@ -10,6 +10,7 @@
 #include "cache-tree.h"
 #include "unpack-trees.h"
 #include "refs.h"
+#include "submodule.h"
 
 /*
  * diff-files
@@ -159,7 +160,7 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
 				continue;
 		}
 
-		if (ce_uptodate(ce) || ce_skip_worktree(ce))
+		if ((ce_uptodate(ce) && !S_ISGITLINK(ce->ce_mode)) || ce_skip_worktree(ce))
 			continue;
 
 		/* If CE_VALID is set, don't look at workdir for file removal */
@@ -176,6 +177,8 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
 			continue;
 		}
 		changed = ce_match_stat(ce, &st, ce_option);
+		if (S_ISGITLINK(ce->ce_mode) && !changed)
+			changed = is_submodule_modified(ce->name);
 		if (!changed) {
 			ce_mark_uptodate(ce);
 			if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
@@ -230,7 +233,8 @@ static int get_stat_data(struct cache_entry *ce,
 			return -1;
 		}
 		changed = ce_match_stat(ce, &st, 0);
-		if (changed) {
+		if (changed
+		    || (S_ISGITLINK(ce->ce_mode) && is_submodule_modified(ce->name))) {
 			mode = ce_mode_from_stat(ce, st.st_mode);
 			sha1 = null_sha1;
 		}
diff --git a/submodule.c b/submodule.c
index 86aad653b7..3f851deb6a 100644
--- a/submodule.c
+++ b/submodule.c
@@ -4,6 +4,7 @@
 #include "diff.h"
 #include "commit.h"
 #include "revision.h"
+#include "run-command.h"
 
 int add_submodule_odb(const char *path)
 {
@@ -112,3 +113,51 @@ void show_submodule_summary(FILE *f, const char *path,
 	}
 	strbuf_release(&sb);
 }
+
+int is_submodule_modified(const char *path)
+{
+	int len;
+	struct child_process cp;
+	const char *argv[] = {
+		"status",
+		"--porcelain",
+		NULL,
+	};
+	char *env[3];
+	struct strbuf buf = STRBUF_INIT;
+
+	strbuf_addf(&buf, "%s/.git/", path);
+	if (!is_directory(buf.buf)) {
+		strbuf_release(&buf);
+		/* The submodule is not checked out, so it is not modified */
+		return 0;
+
+	}
+	strbuf_reset(&buf);
+
+	strbuf_addf(&buf, "GIT_WORK_TREE=%s", path);
+	env[0] = strbuf_detach(&buf, NULL);
+	strbuf_addf(&buf, "GIT_DIR=%s/.git", path);
+	env[1] = strbuf_detach(&buf, NULL);
+	env[2] = NULL;
+
+	memset(&cp, 0, sizeof(cp));
+	cp.argv = argv;
+	cp.env = (const char *const *)env;
+	cp.git_cmd = 1;
+	cp.no_stdin = 1;
+	cp.out = -1;
+	if (start_command(&cp))
+		die("Could not run git status --porcelain");
+
+	len = strbuf_read(&buf, cp.out, 1024);
+	close(cp.out);
+
+	if (finish_command(&cp))
+		die("git status --porcelain failed");
+
+	free(env[0]);
+	free(env[1]);
+	strbuf_release(&buf);
+	return len != 0;
+}
diff --git a/submodule.h b/submodule.h
index 4c0269d679..0773121eb5 100644
--- a/submodule.h
+++ b/submodule.h
@@ -4,5 +4,6 @@
 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);
+int is_submodule_modified(const char *path);
 
 #endif
diff --git a/t/t7506-status-submodule.sh b/t/t7506-status-submodule.sh
index 3ca17abad1..253c334319 100755
--- a/t/t7506-status-submodule.sh
+++ b/t/t7506-status-submodule.sh
@@ -5,34 +5,87 @@ test_description='git status for submodule'
 . ./test-lib.sh
 
 test_expect_success 'setup' '
-	test_create_repo sub
-	cd sub &&
-	: >bar &&
-	git add bar &&
-	git commit -m " Add bar" &&
-	cd .. &&
-	git add sub &&
+	test_create_repo sub &&
+	(
+		cd sub &&
+		: >bar &&
+		git add bar &&
+		git commit -m " Add bar" &&
+		: >foo &&
+		git add foo &&
+		git commit -m " Add foo"
+	) &&
+	echo output > .gitignore &&
+	git add sub .gitignore &&
 	git commit -m "Add submodule sub"
 '
 
 test_expect_success 'status clean' '
-	git status |
-	grep "nothing to commit"
+	git status >output &&
+	grep "nothing to commit" output
 '
+
 test_expect_success 'commit --dry-run -a clean' '
-	git commit --dry-run -a |
-	grep "nothing to commit"
+	test_must_fail git commit --dry-run -a >output &&
+	grep "nothing to commit" output
+'
+
+test_expect_success 'status with modified file in submodule' '
+	(cd sub && git reset --hard) &&
+	echo "changed" >sub/foo &&
+	git status >output &&
+	grep "modified:   sub" output
+'
+
+test_expect_success 'status with modified file in submodule (porcelain)' '
+	(cd sub && git reset --hard) &&
+	echo "changed" >sub/foo &&
+	git status --porcelain >output &&
+	diff output - <<-\EOF
+	 M sub
+	EOF
+'
+
+test_expect_success 'status with added file in submodule' '
+	(cd sub && git reset --hard && echo >foo && git add foo) &&
+	git status >output &&
+	grep "modified:   sub" output
+'
+
+test_expect_success 'status with added file in submodule (porcelain)' '
+	(cd sub && git reset --hard && echo >foo && git add foo) &&
+	git status --porcelain >output &&
+	diff output - <<-\EOF
+	 M sub
+	EOF
+'
+
+test_expect_success 'status with untracked file in submodule' '
+	(cd sub && git reset --hard) &&
+	echo "content" >sub/new-file &&
+	git status >output &&
+	grep "modified:   sub" output
+'
+
+test_expect_success 'status with untracked file in submodule (porcelain)' '
+	git status --porcelain >output &&
+	diff output - <<-\EOF
+	 M sub
+	EOF
 '
+
 test_expect_success 'rm submodule contents' '
 	rm -rf sub/* sub/.git
 '
+
 test_expect_success 'status clean (empty submodule dir)' '
-	git status |
-	grep "nothing to commit"
+	git status >output &&
+	grep "nothing to commit" output
 '
+
 test_expect_success 'status -a clean (empty submodule dir)' '
-	git commit --dry-run -a |
-	grep "nothing to commit"
+	test_must_fail git commit --dry-run -a >output &&
+	grep "nothing to commit" output
 '
 
 test_done