1 files changed, 59 insertions, 4 deletions

diff --git a/run-command.c b/run-command.c
index c90cdc50e3..b05c734d05 100644
--- a/run-command.c
+++ b/run-command.c
@@ -118,7 +118,9 @@ int start_command(struct child_process *cmd)
 		} else {
 			execvp(cmd->argv[0], (char *const*) cmd->argv);
 		}
-		die("exec %s failed.", cmd->argv[0]);
+		trace_printf("trace: exec '%s' failed: %s\n", cmd->argv[0],
+				strerror(errno));
+		exit(127);
 	}
 #else
 	int s0 = -1, s1 = -1, s2 = -1;	/* backups of stdin, stdout, stderr */
@@ -187,6 +189,7 @@ int start_command(struct child_process *cmd)
 #endif
 
 	if (cmd->pid < 0) {
+		int err = errno;
 		if (need_in)
 			close_pair(fdin);
 		else if (cmd->in)
@@ -197,7 +200,9 @@ int start_command(struct child_process *cmd)
 			close(cmd->out);
 		if (need_err)
 			close_pair(fderr);
-		return -ERR_RUN_COMMAND_FORK;
+		return err == ENOENT ?
+			-ERR_RUN_COMMAND_EXEC :
+			-ERR_RUN_COMMAND_FORK;
 	}
 
 	if (need_in)
@@ -236,9 +241,14 @@ static int wait_or_whine(pid_t pid)
 		if (!WIFEXITED(status))
 			return -ERR_RUN_COMMAND_WAITPID_NOEXIT;
 		code = WEXITSTATUS(status);
-		if (code)
+		switch (code) {
+		case 127:
+			return -ERR_RUN_COMMAND_EXEC;
+		case 0:
+			return 0;
+		default:
 			return -code;
-		return 0;
+		}
 	}
 }
 
@@ -342,3 +352,48 @@ int finish_async(struct async *async)
 #endif
 	return ret;
 }
+
+int run_hook(const char *index_file, const char *name, ...)
+{
+	struct child_process hook;
+	const char **argv = NULL, *env[2];
+	char index[PATH_MAX];
+	va_list args;
+	int ret;
+	size_t i = 0, alloc = 0;
+
+	if (access(git_path("hooks/%s", name), X_OK) < 0)
+		return 0;
+
+	va_start(args, name);
+	ALLOC_GROW(argv, i + 1, alloc);
+	argv[i++] = git_path("hooks/%s", name);
+	while (argv[i-1]) {
+		ALLOC_GROW(argv, i + 1, alloc);
+		argv[i++] = va_arg(args, const char *);
+	}
+	va_end(args);
+
+	memset(&hook, 0, sizeof(hook));
+	hook.argv = argv;
+	hook.no_stdin = 1;
+	hook.stdout_to_stderr = 1;
+	if (index_file) {
+		snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
+		env[0] = index;
+		env[1] = NULL;
+		hook.env = env;
+	}
+
+	ret = start_command(&hook);
+	free(argv);
+	if (ret) {
+		warning("Could not spawn %s", argv[0]);
+		return ret;
+	}
+	ret = finish_command(&hook);
+	if (ret == -ERR_RUN_COMMAND_WAITPID_SIGNAL)
+		warning("%s exited due to uncaught signal", argv[0]);
+
+	return ret;
+}