Merge branch 'pw/submodule-process-sigpipe'

When a subprocess to work in a submodule spawned by "git submodule"
fails with SIGPIPE, the parent Git process caught the death of it,
but gave a generic "failed to work in that submodule", which was
misleading.  We now behave as if the parent got SIGPIPE and die.

* pw/submodule-process-sigpipe:
  submodule status: propagate SIGPIPE

builtin/submodule--helper.c

@@ -696,6 +696,7 @@ static void status_submodule(const char *path, const struct object_id *ce_oid,
 
 	if (flags & OPT_RECURSIVE) {
 		struct child_process cpr = CHILD_PROCESS_INIT;
+		int res;
 
 		cpr.git_cmd = 1;
 		cpr.dir = path;
@@ -711,7 +712,10 @@ static void status_submodule(const char *path, const struct object_id *ce_oid,
 		if (flags & OPT_QUIET)
 			strvec_push(&cpr.args, "--quiet");
 
-		if (run_command(&cpr))
+		res = run_command(&cpr);
+		if (res == SIGPIPE + 128)
+			raise(SIGPIPE);
+		else if (res)
 			die(_("failed to recurse into submodule '%s'"), path);
 	}
 

t/t7422-submodule-output.sh

@@ -167,4 +167,11 @@ do
 	'
 done
 
+test_expect_success !MINGW 'git submodule status --recursive propagates SIGPIPE' '
+	{ git submodule status --recursive 2>err; echo $?>status; } |
+		grep -q X/S &&
+	test_must_be_empty err &&
+	test_match_signal 13 "$(cat status)"
+'
+
 test_done