From c68b3f3d64d52cc97e204d1fc039372bbb62dc6e Mon Sep 17 00:00:00 2001
From: Nick Wellnhofer <wellnhofer@aevum.de>
Date: Sun, 13 Dec 2015 19:22:48 +0100
Subject: [PATCH] Fix possible NULL pointer deref in libexslt/functions.c

Based on the patch by mahendra.n. Fixes bug #757663.

https://bugzilla.gnome.org/show_bug.cgi?id=757663
---
 libexslt/functions.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/libexslt/functions.c b/libexslt/functions.c
index b111fd8c..0795a13d 100644
--- a/libexslt/functions.c
+++ b/libexslt/functions.c
@@ -303,6 +303,14 @@ exsltFuncFunctionFunction (xmlXPathParserContextPtr ctxt, int nargs) {
     func = (exsltFuncFunctionData*) xmlHashLookup2 (data->funcs,
 						    ctxt->context->functionURI,
 						    ctxt->context->function);
+    if (func == NULL) {
+        /* Should never happen */
+        xsltGenericError(xsltGenericErrorContext,
+                         "{%s}%s: not found\n",
+                         ctxt->context->functionURI, ctxt->context->function);
+        ctxt->error = XPATH_UNKNOWN_FUNC_ERROR;
+        return;
+    }
 
     /*
      * params handling