Re: [PATCH] Check malloc result in getopt_long

[Pádraig Brady]

On 18/02/15 03:50, Pádraig Brady wrote:
> On 16/02/15 21:55, Tobias Stoeckmann wrote:
>> On Mon, Feb 16, 2015 at 08:57:00PM +0000, Pádraig Brady wrote:
>>> I'm not sure it's generally worth proceeding in OOM conditions
>>> unless there are clear fall backs.  It would be nice to depend on xalloc
>>> and just call xmalloc(). Could this suffice?
>>>
>>>   #ifdef _LIBC
>>>   struct option_list *newp = alloca (sizeof (*newp));
>>>   #else
>>>   struct option_list *newp = xmalloc (sizeof (*newp));
>>>   #endif
>>
>> Yeah, I am fine with that solution.
>> Didn't think about simply using xmalloc there. Maybe it was too easy. :)
> 
> We can't use xmalloc for licensing reasons.
> Anyway it's better for this lib to fall back to a degraded diagnostic than 
> exit.
> Also I noticed a mem leak in the non mem exhaustion case.
> Hopefully the attached addresses all this.

I amended this to break out of the option matching loop
upon memory exhaustion and pushed, but then realised that
this could give a false indication of ambiguous options.
So I pushed the following as well.

thanks,
Pádraig.

>From 8e841aec83c3b75013493e677bc53cc907995140 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C3=A1draig=20Brady?= <address@hidden>
Date: Wed, 18 Feb 2015 22:37:31 +0000
Subject: [PATCH] getopt: give accurate ambiguity diagnostic on mem
 exhaustion

* lib/getopt.c (_getopt_internal_r): The previous commit broke
out the loop too early, which could give a false indication
of ambiguous options under memory exhaustion.
---
 lib/getopt.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lib/getopt.c b/lib/getopt.c
index 6474ba7..212cbf7 100644
--- a/lib/getopt.c
+++ b/lib/getopt.c
@@ -527,6 +527,8 @@ _getopt_internal_r (int argc, char **argv, const char 
*optstring,
                 pfound = p;
                 indfound = option_index;
               }
+            else if (ambig)
+              ; /* Taking simpler path to handling ambiguities.  */
             else if (long_only
                      || pfound->has_arg != p->has_arg
                      || pfound->flag != p->flag
@@ -539,10 +541,9 @@ _getopt_internal_r (int argc, char **argv, const char 
*optstring,
                 struct option_list *newp = malloc (sizeof (*newp));
                 if (newp == NULL)
                   {
-                    ambig = 1; /* Use simpler fallback message.  */
                     free_option_list (ambig_list);
                     ambig_list = NULL;
-                    break;
+                    ambig = 1; /* Use simpler fallback message.  */
                   }
                 else
 #endif
-- 
2.1.0