1 files changed, 80 insertions, 0 deletions
diff --git a/submodule.c b/submodule.c
index 50f213e926..e3e0b455ea 100644
--- a/submodule.c
+++ b/submodule.c
@@ -759,6 +759,86 @@ unsigned is_submodule_modified(const char *path, int ignore_untracked)
 	return dirty_submodule;
 }
 
+int submodule_uses_gitfile(const char *path)
+{
+	struct child_process cp;
+	const char *argv[] = {
+		"submodule",
+		"foreach",
+		"--quiet",
+		"--recursive",
+		"test -f .git",
+		NULL,
+	};
+	struct strbuf buf = STRBUF_INIT;
+	const char *git_dir;
+
+	strbuf_addf(&buf, "%s/.git", path);
+	git_dir = read_gitfile(buf.buf);
+	if (!git_dir) {
+		strbuf_release(&buf);
+		return 0;
+	}
+	strbuf_release(&buf);
+
+	/* Now test that all nested submodules use a gitfile too */
+	memset(&cp, 0, sizeof(cp));
+	cp.argv = argv;
+	cp.env = local_repo_env;
+	cp.git_cmd = 1;
+	cp.no_stdin = 1;
+	cp.no_stderr = 1;
+	cp.no_stdout = 1;
+	cp.dir = path;
+	if (run_command(&cp))
+		return 0;
+
+	return 1;
+}
+
+int ok_to_remove_submodule(const char *path)
+{
+	struct stat st;
+	ssize_t len;
+	struct child_process cp;
+	const char *argv[] = {
+		"status",
+		"--porcelain",
+		"-u",
+		"--ignore-submodules=none",
+		NULL,
+	};
+	struct strbuf buf = STRBUF_INIT;
+	int ok_to_remove = 1;
+
+	if ((lstat(path, &st) < 0) || is_empty_dir(path))
+		return 1;
+
+	if (!submodule_uses_gitfile(path))
+		return 0;
+
+	memset(&cp, 0, sizeof(cp));
+	cp.argv = argv;
+	cp.env = local_repo_env;
+	cp.git_cmd = 1;
+	cp.no_stdin = 1;
+	cp.out = -1;
+	cp.dir = path;
+	if (start_command(&cp))
+		die("Could not run 'git status --porcelain -uall --ignore-submodules=none' in submodule %s", path);
+
+	len = strbuf_read(&buf, cp.out, 1024);
+	if (len > 2)
+		ok_to_remove = 0;
+	close(cp.out);
+
+	if (finish_command(&cp))
+		die("'git status --porcelain -uall --ignore-submodules=none' failed in submodule %s", path);
+
+	strbuf_release(&buf);
+	return ok_to_remove;
+}
+
 static int find_first_merges(struct object_array *result, const char *path,
 		struct commit *a, struct commit *b)
 {