git: use run_command() to execute dashed externals

We used to simply try calling execvp(); if it succeeded, then we were done and the new program was running. If it didn't, then we knew that it wasn't a valid command. Unfortunately, this interacted badly with the new pager handling. Now that git remains the parent process and the pager is spawned, git has to hang around until the pager is finished. We install an atexit handler to do this, but that handler never gets called if we successfully run execvp. You could see this behavior by running any dashed external using a pager (e.g., "git -p stash list"). The command finishes running, but the pager is still going. In the case of less, it then gets an error reading from the terminal and exits, potentially leaving the terminal in a broken state (and not showing the output). This patch just uses run_command() to try running the dashed external. The parent git process then waits for the external process to complete and then handles the pager cleanup as it would for an internal command. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Jeff King committed Jan 28, 2009 at 02:38 UTC d8e96fd86d415554a9c2e09ffb929a9e22fdad25

1 file changed +13 -4

git.c

+13 -4

@@ -2,6 +2,7 @@

2 #include "exec_cmd.h"

3 #include "cache.h"

4 #include "quote.h"

5 +#include "run-command.h"

7 const char git_usage_string[] =

8 "git [--version] [--exec-path[=GIT_EXEC_PATH]] [-p|--paginate|--no-pager] [--bare] [--git-dir=GIT_DIR] [--work-tree=GIT_WORK_TREE] [--help] COMMAND [ARGS]";

@@ -392,6 +393,7 @@ static void execv_dashed_external(const char **argv)

393 {

394 struct strbuf cmd = STRBUF_INIT;

395 const char *tmp;

396 + int status;

397

398 strbuf_addf(&cmd, "git-%s", argv[0]);

399

@@ -406,10 +408,17 @@ static void execv_dashed_external(const char **argv)

408

409 trace_argv_printf(argv, "trace: exec:");

410

409 - /* execvp() can only ever return if it fails */

410 - execvp(cmd.buf, (char **)argv);

411 -

412 - trace_printf("trace: exec failed: %s\n", strerror(errno));

411 + /*

412 + * if we fail because the command is not found, it is

413 + * OK to return. Otherwise, we just pass along the status code.

414 + */

415 + status = run_command_v_opt(argv, 0);

416 + if (status != -ERR_RUN_COMMAND_EXEC) {

417 + if (IS_RUN_COMMAND_ERR(status))

418 + die("unable to run '%s'", argv[0]);

419 + exit(-status);

420 + }

421 + errno = ENOENT; /* as if we called execvp */

422

423 argv[0] = tmp;

424