[libxml2] Fix memory leak in xmlXPathEvalExpression()

[Daniel Veillard <veillard src gnome org>]

commit 729601f15772c19778062b98bd0716d8f5c2af3b
Author: Martin <gzlist googlemail com>
Date:   Mon Oct 12 22:42:26 2009 +0200

    Fix memory leak in xmlXPathEvalExpression()
    
    * xpath.c: plug some leaks when parsing misformed XPath expressions
    * python/tests/xpathleak.py: expand the regression tests for those

 python/tests/xpathleak.py |   14 +++++++++++++-
 xpath.c                   |    2 ++
 2 files changed, 15 insertions(+), 1 deletions(-)
---
diff --git a/python/tests/xpathleak.py b/python/tests/xpathleak.py
index dcc144c..39f49e3 100644
--- a/python/tests/xpathleak.py
+++ b/python/tests/xpathleak.py
@@ -15,6 +15,14 @@ expect="""--> Invalid expression
 --> xmlXPathEval: evaluation failed
 --> Invalid expression
 --> xmlXPathEval: evaluation failed
+--> Invalid expression
+--> xmlXPathEval: evaluation failed
+--> Invalid expression
+--> xmlXPathEval: evaluation failed
+--> Invalid expression
+--> xmlXPathEval: evaluation failed
+--> Invalid expression
+--> xmlXPathEval: evaluation failed
 """
 err=""
 def callback(ctx, str):
@@ -27,7 +35,11 @@ libxml2.registerErrorHandler(callback, "-->")
 doc = libxml2.parseDoc("<fish/>")
 ctxt = doc.xpathNewContext()
 ctxt.setContextNode(doc)
-for expr in (":false()","bad:()","bad(:)",":bad(:)","bad:(:)","bad:bad(:)"):
+badexprs = (
+	":false()", "bad:()", "bad(:)", ":bad(:)", "bad:(:)", "bad:bad(:)",
+	"a:/b", "/c:/d", "//e:/f", "g://h"
+	)
+for expr in badexprs:
 	try:
 		ctxt.xpathEval(expr)
 	except libxml2.xpathError, e:
diff --git a/xpath.c b/xpath.c
index 5b84d22..8482c40 100644
--- a/xpath.c
+++ b/xpath.c
@@ -11333,6 +11333,7 @@ xmlXPathCompRelativeLocationPath
 	SKIP_BLANKS;
     }
     xmlXPathCompStep(ctxt);
+    CHECK_ERROR;
     SKIP_BLANKS;
     while (CUR == '/') {
 	if ((CUR == '/') && (NXT(1) == '/')) {
@@ -11392,6 +11393,7 @@ xmlXPathCompLocationPath(xmlXPathParserContextPtr ctxt) {
 		     (CUR == '@') || (CUR == '*')))
 		    xmlXPathCompRelativeLocationPath(ctxt);
 	    }
+	    CHECK_ERROR;
 	}
     }
 }