From: René Scharfe <l.s.r@web.de>
Date: Fri, 17 Mar 2017 23:21:11 GMT
Subject: Re: [PATCH] receive-pack: simplify run_update_post_hook()
Message-ID: <f61a1089-833b-2883-deab-f97cb77cef96@web.de>
In-Reply-To: <20170317222320.nsg3yk3nopjadr5t@sigill.intra.peff.net>

Am 17.03.2017 um 23:23 schrieb Jeff King:
> On Fri, Mar 17, 2017 at 11:02:13PM +0100, René Scharfe wrote:
>
>> Instead of counting the arguments to see if there are any and then
>> building the full command use a single loop and add the hook command
>> just before the first argument.  This reduces duplication and overall
>> code size.
>
> Yeah, I agree one loop is nicer.
>
>> -	argv_array_push(&proc.args, hook);
>>  	for (cmd = commands; cmd; cmd = cmd->next) {
>>  		if (cmd->error_string || cmd->did_not_exist)
>>  			continue;
>> +		if (!proc.args.argc)
>> +			argv_array_push(&proc.args, hook);
>>  		argv_array_push(&proc.args, cmd->ref_name);
>>  	}
>> +	if (!proc.args.argc)
>> +		return;
>
> It looks at first like the result leaks, because you have to realize
> that the push will modify proc.args.argc. I wonder if:
>
>   argv_array_push(&proc.args, hook);
>   for (cmd = commands; cmd; cmd = cmd->next) {
> 	if (!cmd->error_string && !cmd->did_not_exist)
> 		argv_array_push(&proc.args, cmd->ref_name);
>   }
>
>   if (proc.args.argc == 1) {
> 	argv_array_clear(&proc.args);
> 	return;
>   }
>
> would be more obvious (at the cost of a pointless malloc in the corner
> case. I can live with it either way.

Sure, that's even simpler.  I don't know how often the no-args branch 
would be taken and if the extra allocation would even matter -- that's 
why I tried to avoid it -- but probably the answers are not often and 
not much.  The only test case that hits it is for the deletion of a 
non-existent ref.

René