Re: [RFC/PATCH] avoid SIGPIPE warnings for aliases

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

Jeff King <peff@peff.net> writes:

> Maybe the right rule is "if we are using the shell to execute, do not
> mention SIGPIPE"? It seems a little iffy at first, but:
>
>   1. It tends to coincide with direct use of internal tools versus
>      external tools.
>
>   2. We do not reliably get SIGPIPE there, anyway, since most shells
>      will convert it into exit code 141 before we see it.
>
> I.e., something like:

Hmph.  That may be a good heuristics, but I wonder if we also want
to special case WIFEXITED(status) && WEXITSTATUS(status) == 141 to
pretend as if nothing went wrong, when ignore_sigpipe is in effect?

> diff --git a/run-command.c b/run-command.c
> index 24eaad5..8bd0b08 100644
> --- a/run-command.c
> +++ b/run-command.c
> @@ -226,7 +226,7 @@ static inline void set_cloexec(int fd)
>  		fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
>  }
>  
> -static int wait_or_whine(pid_t pid, const char *argv0)
> +static int wait_or_whine(pid_t pid, const char *argv0, int ignore_sigpipe)
>  {
>  	int status, code = -1;
>  	pid_t waiting;
> @@ -242,7 +242,8 @@ static int wait_or_whine(pid_t pid, const char *argv0)
>  		error("waitpid is confused (%s)", argv0);
>  	} else if (WIFSIGNALED(status)) {
>  		code = WTERMSIG(status);
> -		if (code != SIGINT && code != SIGQUIT)
> +		if (code != SIGINT && code != SIGQUIT &&
> +		    (!ignore_sigpipe || code != SIGPIPE))
>  			error("%s died of signal %d", argv0, code);
>  		/*
>  		 * This return value is chosen so that code & 0xff
> @@ -433,7 +434,7 @@ fail_pipe:
>  		 * At this point we know that fork() succeeded, but execvp()
>  		 * failed. Errors have been reported to our stderr.
>  		 */
> -		wait_or_whine(cmd->pid, cmd->argv[0]);
> +		wait_or_whine(cmd->pid, cmd->argv[0], 0);
>  		failed_errno = errno;
>  		cmd->pid = -1;
>  	}
> @@ -538,7 +539,7 @@ int finish_command(struct child_process *cmd)
>  
>  int finish_command(struct child_process *cmd)
>  {
> -	return wait_or_whine(cmd->pid, cmd->argv[0]);
> +	return wait_or_whine(cmd->pid, cmd->argv[0], cmd->use_shell);
>  }
>  
>  int run_command(struct child_process *cmd)
> @@ -725,7 +726,7 @@ int finish_async(struct async *async)
>  int finish_async(struct async *async)
>  {
>  #ifdef NO_PTHREADS
> -	return wait_or_whine(async->pid, "child process");
> +	return wait_or_whine(async->pid, "child process", 0);
>  #else
>  	void *ret = (void *)(intptr_t)(-1);
>