execv_dashed_external: use child_process struct

When we run a dashed external, we use the one-liner
run_command_v_opt() to do so. Let's switch to using a
child_process struct, which has two advantages:

  1. We can drop all of the allocation and cleanup code for
     building our custom argv array, and just rely on the
     builtin argv_array (at the minor cost of doing a few
     extra mallocs).

  2. We have access to the complete range of child_process
     options, not just the ones that the "_opt()" form can
     forward.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git.c b/git.c
index dce529f..d0e04d5 100644 (file)
--- a/git.c
+++ b/git.c
@@ -575,8 +575,7 @@ static void handle_builtin(int argc, const char **argv)
 
 static void execv_dashed_external(const char **argv)
 {
-       struct strbuf cmd = STRBUF_INIT;
-       const char *tmp;
+       struct child_process cmd = CHILD_PROCESS_INIT;
        int status;
 
        if (get_super_prefix())
@@ -586,30 +585,20 @@ static void execv_dashed_external(const char **argv)
                use_pager = check_pager_config(argv[0]);
        commit_pager_choice();
 
-       strbuf_addf(&cmd, "git-%s", argv[0]);
+       argv_array_pushf(&cmd.args, "git-%s", argv[0]);
+       argv_array_pushv(&cmd.args, argv + 1);
+       cmd.clean_on_exit = 1;
+       cmd.silent_exec_failure = 1;
 
-       /*
-        * argv[0] must be the git command, but the argv array
-        * belongs to the caller, and may be reused in
-        * subsequent loop iterations. Save argv[0] and
-        * restore it on error.
-        */
-       tmp = argv[0];
-       argv[0] = cmd.buf;
-
-       trace_argv_printf(argv, "trace: exec:");
+       trace_argv_printf(cmd.args.argv, "trace: exec:");
 
        /*
         * if we fail because the command is not found, it is
         * OK to return. Otherwise, we just pass along the status code.
         */
-       status = run_command_v_opt(argv, RUN_SILENT_EXEC_FAILURE | RUN_CLEAN_ON_EXIT);
+       status = run_command(&cmd);
        if (status >= 0 || errno != ENOENT)
                exit(status);
-
-       argv[0] = tmp;
-
-       strbuf_release(&cmd);
 }
 
 static int run_argv(int *argcp, const char ***argv)