From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Thu, 12 Mar 2009 00:53:48 +0000 (+0000)
Subject: Fix core dump due to null-pointer dereference in to_char() when datetime
X-Git-Url: http://git.postgresql.org/gitweb/?a=commitdiff_plain;h=b06d421e6caa7a49e11bb27f77ff63cba33ef5dd;p=users%2Fbernd%2Fpostgres.git

Fix core dump due to null-pointer dereference in to_char() when datetime
format codes are misapplied to a numeric argument.  (The code still produces
a pretty bogus error message in such cases, but I'll settle for stopping the
crash for now.)  Per bug #4700 from Sergey Burladyan.

Problem exists in all supported branches, so patch all the way back.
In HEAD, also clean up some ugly coding in the nearby cache management
code.
---

diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index 6d69ce1b98..f82fd2b25b 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -347,7 +347,7 @@ static int	DCHCounter = 0;
 
 /* global cache for --- number part */
 static NUMCacheEntry NUMCache[NUM_CACHE_FIELDS + 1];
-static NUMCacheEntry *last_NUMCacheEntry;
+static NUMCacheEntry *last_NUMCacheEntry = NUMCache + 0;
 
 static int	n_NUMCache = 0;		/* number of entries */
 static int	NUMCounter = 0;