run_command(): help callers distinguish errors

diff --git a/run-command.c b/run-command.c
index a3b28a64dc2d1b888b0ba2a135be10fe04651201..44fccc9d5ef4d01eb3c73d6ce8cfbb0cfff0362b 100644 (file)
--- a/run-command.c
+++ b/run-command.c
@@ -68,6 +68,7 @@ int start_command(struct child_process *cmd)
        trace_argv_printf(cmd->argv, "trace: run_command:");
 
 #ifndef __MINGW32__
+       fflush(NULL);
        cmd->pid = fork();
        if (!cmd->pid) {
                if (cmd->no_stdin)
@@ -110,12 +111,16 @@ int start_command(struct child_process *cmd)
                                        unsetenv(*cmd->env);
                        }
                }
+               if (cmd->preexec_cb)
+                       cmd->preexec_cb();
                if (cmd->git_cmd) {
                        execv_git_cmd(cmd->argv);
                } 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 */
@@ -184,6 +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)
@@ -194,7 +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)
@@ -233,9 +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;
+               }
        }
 }
 
@@ -270,14 +283,6 @@ int run_command_v_opt(const char **argv, int opt)
        return run_command(&cmd);
 }
 
-int run_command_v_opt_cd(const char **argv, int opt, const char *dir)
-{
-       struct child_process cmd;
-       prepare_run_command_v_opt(&cmd, argv, opt);
-       cmd.dir = dir;
-       return run_command(&cmd);
-}
-
 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
 {
        struct child_process cmd;
@@ -304,6 +309,9 @@ int start_async(struct async *async)
        async->out = pipe_out[0];
 
 #ifndef __MINGW32__
+       /* Flush stdio before fork() to avoid cloning buffers */
+       fflush(NULL);
+
        async->pid = fork();
        if (async->pid < 0) {
                error("fork (async) failed: %s", strerror(errno));