[libxml2] Fix an off by one pointer access

[Daniel Veillard <veillard src gnome org>]

commit d8e1faeaa99c7a7c07af01c1c72de352eb590a3e
Author: JÃri Aedla <asd ut ee>
Date:   Mon May 7 15:06:56 2012 +0800

    Fix an off by one pointer access
    
    getting out of the range of memory allocated for xpointer decoding

 xpointer.c |   15 ++++-----------
 1 files changed, 4 insertions(+), 11 deletions(-)
---
diff --git a/xpointer.c b/xpointer.c
index 37afa3a..0b463dd 100644
--- a/xpointer.c
+++ b/xpointer.c
@@ -1007,21 +1007,14 @@ xmlXPtrEvalXPtrPart(xmlXPathParserContextPtr ctxt, xmlChar *name) {
 		NEXT;
 		break;
 	    }
-	    *cur++ = CUR;
 	} else if (CUR == '(') {
 	    level++;
-	    *cur++ = CUR;
 	} else if (CUR == '^') {
-	    NEXT;
-	    if ((CUR == ')') || (CUR == '(') || (CUR == '^')) {
-		*cur++ = CUR;
-	    } else {
-		*cur++ = '^';
-		*cur++ = CUR;
-	    }
-	} else {
-	    *cur++ = CUR;
+            if ((NXT(1) == ')') || (NXT(1) == '(') || (NXT(1) == '^')) {
+                NEXT;
+            }
 	}
+        *cur++ = CUR;
 	NEXT;
     }
     *cur = 0;