Re: [PATCH 2/3] xdiff: refactor a function

> Junio C Hamano <gitster@pobox.com> writes:
> 
>>>   int xdl_merge(mmfile_t *orig, mmfile_t *mf1, mmfile_t *mf2,
>>>   		xmparam_t const *xmp, mmbuffer_t *result)
>>>   {
>>> -	xdchange_t *xscr1, *xscr2;
>>> -	xdfenv_t xe1, xe2;
>>> -	int status;
>>> +	xdchange_t *xscr1 = NULL, *xscr2 = NULL;
>>> +	xdfenv_t xe1 = { 0 }, xe2 = { 0 };
>>> +	int status = -1;
>>>   	xpparam_t const *xpp = &xmp->xpp;
>>>   
>>>   	result->ptr = NULL;
>>>   	result->size = 0;
>>>   
>>> -	if (xdl_do_diff(orig, mf1, xpp, &xe1) < 0) {
>>> -		return -1;
>>> -	}
>>> -	if (xdl_do_diff(orig, mf2, xpp, &xe2) < 0) {
>>> -		xdl_free_env(&xe1);
>>> -		return -1;
>>> -	}
>>
>> OK, xdl_do_diff() calls xdl_free_env(xe) before an error return (I
>> didn't check if patience and histogram also do so correctly), so the
>> original was not leaking xe1 or xe2.
> 
> After I wrote the above, I took a brief look at patience and histogram,
> and it does not seem to release resources held by "env" when it signals
> a failure by returning a negative value.  So it seems that the original
> used with patience or histogram were leaking env when it failed, and
> this patch plugs that small leak.
> 
> If that is indeed the case, please note it in the proposed log
> message.