1 files changed, 43 insertions, 32 deletions

diff --git a/submodule.c b/submodule.c
index 7c3c4b17f..2ee970572 100644
--- a/submodule.c
+++ b/submodule.c
@@ -1112,67 +1112,78 @@ out:
 
 unsigned is_submodule_modified(const char *path, int ignore_untracked)
 {
-	ssize_t len;
 	struct child_process cp = CHILD_PROCESS_INIT;
-	const char *argv[] = {
-		"status",
-		"--porcelain",
-		NULL,
-		NULL,
-	};
 	struct strbuf buf = STRBUF_INIT;
+	FILE *fp;
 	unsigned dirty_submodule = 0;
-	const char *line, *next_line;
 	const char *git_dir;
+	int ignore_cp_exit_code = 0;
 
 	strbuf_addf(&buf, "%s/.git", path);
 	git_dir = read_gitfile(buf.buf);
 	if (!git_dir)
 		git_dir = buf.buf;
-	if (!is_directory(git_dir)) {
+	if (!is_git_directory(git_dir)) {
+		if (is_directory(git_dir))
+			die(_("'%s' not recognized as a git repository"), git_dir);
 		strbuf_release(&buf);
 		/* The submodule is not checked out, so it is not modified */
 		return 0;
-
 	}
 	strbuf_reset(&buf);
 
+	argv_array_pushl(&cp.args, "status", "--porcelain=2", NULL);
 	if (ignore_untracked)
-		argv[2] = "-uno";
+		argv_array_push(&cp.args, "-uno");
 
-	cp.argv = argv;
 	prepare_submodule_repo_env(&cp.env_array);
 	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' in submodule %s", path);
+		die("Could not run 'git status --porcelain=2' in submodule %s", path);
 
-	len = strbuf_read(&buf, cp.out, 1024);
-	line = buf.buf;
-	while (len > 2) {
-		if ((line[0] == '?') && (line[1] == '?')) {
+	fp = xfdopen(cp.out, "r");
+	while (strbuf_getwholeline(&buf, fp, '\n') != EOF) {
+		/* regular untracked files */
+		if (buf.buf[0] == '?')
 			dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
-			if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
-				break;
-		} else {
-			dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
-			if (ignore_untracked ||
-			    (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED))
-				break;
+
+		if (buf.buf[0] == 'u' ||
+		    buf.buf[0] == '1' ||
+		    buf.buf[0] == '2') {
+			/* T = line type, XY = status, SSSS = submodule state */
+			if (buf.len < strlen("T XY SSSS"))
+				die("BUG: invalid status --porcelain=2 line %s",
+				    buf.buf);
+
+			if (buf.buf[5] == 'S' && buf.buf[8] == 'U')
+				/* nested untracked file */
+				dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
+
+			if (buf.buf[0] == 'u' ||
+			    buf.buf[0] == '2' ||
+			    memcmp(buf.buf + 5, "S..U", 4))
+				/* other change */
+				dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
 		}
-		next_line = strchr(line, '\n');
-		if (!next_line)
+
+		if ((dirty_submodule & DIRTY_SUBMODULE_MODIFIED) &&
+		    ((dirty_submodule & DIRTY_SUBMODULE_UNTRACKED) ||
+		     ignore_untracked)) {
+			/*
+			 * We're not interested in any further information from
+			 * the child any more, neither output nor its exit code.
+			 */
+			ignore_cp_exit_code = 1;
 			break;
-		next_line++;
-		len -= (next_line - line);
-		line = next_line;
+		}
 	}
-	close(cp.out);
+	fclose(fp);
 
-	if (finish_command(&cp))
-		die("'git status --porcelain' failed in submodule %s", path);
+	if (finish_command(&cp) && !ignore_cp_exit_code)
+		die("'git status --porcelain=2' failed in submodule %s", path);
 
 	strbuf_release(&buf);
 	return dirty_submodule;