Re: [PATCH 1/3] After chdir to run grep, return to old directory

[Junio C Hamano <gitster@pobox.com>]

David Turner <dturner@twopensource.com> writes:

> This causes my test to pass and generally seems correct to me.

Yes, this approach is very sensible, and I'll queue.

But watchman support _should_ be prepared for a program that does
not do this.  Developing your support in on a codebase with this
patch may be sweeping a bug in your code under the rug.

Thanks both for working on your respective changes ;-).

>
> On Tue, 2014-05-06 at 23:00 -0400, Jeff King wrote:
> ...
>> That being said, this really seems like something that the run-command
>> interface should be doing, since it can handle the chdir in the forked
>> child. And indeed, it seems to support that.
>> 
>> Maybe:
>> 
>> -- >8 --
>> Subject: grep: use run-command's "dir" option for --open-files-in-pager
>> 
>> Git generally changes directory to the repository root on
>> startup.  When running "grep --open-files-in-pager" from a
>> subdirectory, we chdir back to the original directory before
>> running the pager, so that we can feed the relative
>> pathnames to the pager.
>> 
>> We currently do this chdir manually, but we can ask
>> run_command to do it for us. This is fewer lines of code,
>> and as a bonus, the chdir is limited to the child process,
>> which avoids any unexpected surprises for code running after
>> the pager (there isn't any currently, but this is
>> future-proofing).
>> 
>> Signed-off-by: Jeff King <peff@peff.net>
>> ---
>>  builtin/grep.c | 4 +---
>>  1 file changed, 1 insertion(+), 3 deletions(-)
>> 
>> diff --git a/builtin/grep.c b/builtin/grep.c
>> index 69ac2d8..43af5b7 100644
>> --- a/builtin/grep.c
>> +++ b/builtin/grep.c
>> @@ -361,9 +361,7 @@ static void run_pager(struct grep_opt *opt, const char *prefix)
>>  		argv[i] = path_list->items[i].string;
>>  	argv[path_list->nr] = NULL;
>>  
>> -	if (prefix && chdir(prefix))
>> -		die(_("Failed to chdir: %s"), prefix);
>> -	status = run_command_v_opt(argv, RUN_USING_SHELL);
>> +	status = run_command_v_opt_cd_env(argv, RUN_USING_SHELL, prefix, NULL);
>>  	if (status)
>>  		exit(status);
>>  	free(argv);