[libxml2] Fix a leak in XPath compilation

[Daniel Veillard <veillard src gnome org>]

commit 2f3523f61f1c7a2a0521c2f6c0db6c80e1cc4111
Author: Daniel Veillard <veillard redhat com>
Date:   Fri Oct 15 18:30:29 2010 +0200

    Fix a leak in XPath compilation
    
    Sometimes a not well formed XPath expression could lead to a
    leak as reported by Ralf Junker <ralfjunker gmx de>

 xpath.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/xpath.c b/xpath.c
index 8b77af3..9d47618 100644
--- a/xpath.c
+++ b/xpath.c
@@ -11261,7 +11261,10 @@ xmlXPathCompStep(xmlXPathParserContextPtr ctxt) {
 	    }
 	}
 
-	CHECK_ERROR;
+        if (ctxt->error != XPATH_EXPRESSION_OK) {
+            xmlFree(name);
+            return;
+        }
 
 	name = xmlXPathCompNodeTest(ctxt, &test, &type, &prefix, name);
 	if (test == 0)