Ensure xmlFree(NULL) is a no-op instead of a core dump. Per report from

Sergey Burladyan, there are at least some dank corners of libxml2 that
assume this behavior, even though their published documentation suggests
they shouldn't.

This is only really a live problem in 8.3, but the code is still there
for possible debugging use in HEAD, so patch both branches.

diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index f6292b913772cb0a1e54ae99d78928bb794310e5..9b34a7abbc7cf8a7a717ac8472e51a569a115fb8 100644 (file)
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -1293,7 +1293,9 @@ xml_repalloc(void *ptr, size_t size)
 static void
 xml_pfree(void *ptr)
 {
-       pfree(ptr);
+       /* At least some parts of libxml assume xmlFree(NULL) is allowed */
+       if (ptr)
+               pfree(ptr);
 }