Merge branch 'jk/submodule-init-segv-fix'

Fix a segv in 'submodule init' when url is not given for a submodule.

* jk/submodule-init-segv-fix:
  submodule_init: die cleanly on submodules without url defined

Author: gitster

builtin/submodule--helper.c

@@ -376,12 +376,12 @@ static void init_submodule(const char *path, const char *prefix, int quiet)
 	strbuf_reset(&sb);
 	strbuf_addf(&sb, "submodule.%s.url", sub->name);
 	if (git_config_get_string(sb.buf, &url)) {
-		url = xstrdup(sub->url);
-
-		if (!url)
+		if (!sub->url)
 			die(_("No url found for submodule path '%s' in .gitmodules"),
 				displaypath);
 
+		url = xstrdup(sub->url);
+
 		/* Possibly a url relative to parent */
 		if (starts_with_dot_dot_slash(url) ||
 		    starts_with_dot_slash(url)) {

t/t7400-submodule-basic.sh

@@ -38,6 +38,14 @@ test_expect_success 'submodule update aborts on missing .gitmodules file' '
 	test_i18ngrep "Submodule path .sub. not initialized" actual
 '
 
+test_expect_success 'submodule update aborts on missing gitmodules url' '
+	test_when_finished "git update-index --remove sub" &&
+	git update-index --add --cacheinfo 160000,$(git rev-parse HEAD),sub &&
+	test_when_finished "rm -f .gitmodules" &&
+	git config -f .gitmodules submodule.s.path sub &&
+	test_must_fail git submodule init
+'
+
 test_expect_success 'configuration parsing' '
 	test_when_finished "rm -f .gitmodules" &&
 	cat >.gitmodules <<-\EOF &&