[PATCH] libiberty: Make `objalloc_free' `free'-like WRT null pointer

[Maciej W. Rozycki]

Inspired by a suggestion from Jan Beulich to make one of `objalloc_free' 
callers `free'-like with respect to null pointer argument handling make 
the function return with no action taken rather than crashing when such 
a pointer is passed.  This is to make the API consistent with ISO C and 
to relieve all the callers from having to check for a null pointer.

	libiberty/
	* objalloc.c (objalloc_free): Don't use the pointer passed if 
	null.	
---
Hi,

 This has been raised in a binutils patch review[1].  OK to apply, and 
then right away, since libiberty is an auxiliary library and technically 
not a part of the compiler suite, plus the change should be trivially 
safe?

References:

[1] "BFD: Prevent a crash on freeing a BFD's uninitialized section hash", 
    <https://inbox.sourceware.org/binutils/23685606-02a1-4416-978a-3c9907c5a171@suse.com/>.

  Maciej
---
 libiberty/objalloc.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

binutils-libiberty-objalloc-free-null.diff
Index: binutils-gdb/libiberty/objalloc.c
===================================================================
--- binutils-gdb.orig/libiberty/objalloc.c
+++ binutils-gdb/libiberty/objalloc.c
@@ -178,7 +178,7 @@ objalloc_free (struct objalloc *o)
 {
   struct objalloc_chunk *l;
 
-  l = (struct objalloc_chunk *) o->chunks;
+  l = o != NULL ? (struct objalloc_chunk *) o->chunks : NULL;
   while (l != NULL)
     {
       struct objalloc_chunk *next;