[libxml2] xpointer : fixing Null Pointers

[Daniel Veillard <veillard src gnome org>]

commit f5496a1ef43ab46211c772cd7a183e719ab24bb5
Author: Gaurav Gupta <g gupta samsung com>
Date:   Tue Oct 7 17:09:35 2014 +0800

    xpointer : fixing Null Pointers
    
    For https://bugzilla.gnome.org/show_bug.cgi?id=738053
    At many places in xpointer.c
    Null check is missing which is dereferenced at later places.

 xpointer.c |   28 ++++++++++++++++++++++++++++
 1 files changed, 28 insertions(+), 0 deletions(-)
---
diff --git a/xpointer.c b/xpointer.c
index 6c8516f..4b4ac2e 100644
--- a/xpointer.c
+++ b/xpointer.c
@@ -1375,6 +1375,8 @@ xmlXPtrEval(const xmlChar *str, xmlXPathContextPtr ctx) {
        return(NULL);
 
     ctxt = xmlXPathNewParserContext(str, ctx);
+    if (ctxt == NULL)
+       return(NULL);
     ctxt->xptr = 1;
     xmlXPtrEvalXPointer(ctxt);
 
@@ -1807,6 +1809,8 @@ xmlXPtrStartPointFunction(xmlXPathParserContextPtr ctxt, int nargs) {
         */
        tmp = xmlXPtrNewLocationSetNodeSet(obj->nodesetval);
        xmlXPathFreeObject(obj);
+       if (tmp == NULL)
+            XP_ERROR(XPATH_MEMORY_ERROR)
        obj = tmp;
     }
 
@@ -1901,10 +1905,16 @@ xmlXPtrEndPointFunction(xmlXPathParserContextPtr ctxt, int nargs) {
         */
        tmp = xmlXPtrNewLocationSetNodeSet(obj->nodesetval);
        xmlXPathFreeObject(obj);
+       if (tmp == NULL)
+            XP_ERROR(XPATH_MEMORY_ERROR)
        obj = tmp;
     }
 
     newset = xmlXPtrLocationSetCreate(NULL);
+    if (newset == NULL) {
+       xmlXPathFreeObject(obj);
+        XP_ERROR(XPATH_MEMORY_ERROR);
+    }
     oldset = (xmlLocationSetPtr) obj->user;
     if (oldset != NULL) {
        int i;
@@ -2049,6 +2059,8 @@ xmlXPtrRangeFunction(xmlXPathParserContextPtr ctxt, int nargs) {
         */
        tmp = xmlXPtrNewLocationSetNodeSet(set->nodesetval);
        xmlXPathFreeObject(set);
+       if (tmp == NULL)
+            XP_ERROR(XPATH_MEMORY_ERROR)
        set = tmp;
     }
     oldset = (xmlLocationSetPtr) set->user;
@@ -2057,6 +2069,10 @@ xmlXPtrRangeFunction(xmlXPathParserContextPtr ctxt, int nargs) {
      * The loop is to compute the covering range for each item and add it
      */
     newset = xmlXPtrLocationSetCreate(NULL);
+    if (newset == NULL) {
+       xmlXPathFreeObject(set);
+        XP_ERROR(XPATH_MEMORY_ERROR);
+    }
     for (i = 0;i < oldset->locNr;i++) {
        xmlXPtrLocationSetAdd(newset,
                xmlXPtrCoveringRange(ctxt, oldset->locTab[i]));
@@ -2195,6 +2211,8 @@ xmlXPtrRangeInsideFunction(xmlXPathParserContextPtr ctxt, int nargs) {
         */
        tmp = xmlXPtrNewLocationSetNodeSet(set->nodesetval);
        xmlXPathFreeObject(set);
+       if (tmp == NULL)
+            XP_ERROR(XPATH_MEMORY_ERROR)
        set = tmp;
     }
     oldset = (xmlLocationSetPtr) set->user;
@@ -2203,6 +2221,10 @@ xmlXPtrRangeInsideFunction(xmlXPathParserContextPtr ctxt, int nargs) {
      * The loop is to compute the covering range for each item and add it
      */
     newset = xmlXPtrLocationSetCreate(NULL);
+    if (newset == NULL) {
+       xmlXPathFreeObject(set);
+        XP_ERROR(XPATH_MEMORY_ERROR);
+    }
     for (i = 0;i < oldset->locNr;i++) {
        xmlXPtrLocationSetAdd(newset,
                xmlXPtrInsideRange(ctxt, oldset->locTab[i]));
@@ -2796,6 +2818,10 @@ xmlXPtrStringRangeFunction(xmlXPathParserContextPtr ctxt, int nargs) {
 
     set = valuePop(ctxt);
     newset = xmlXPtrLocationSetCreate(NULL);
+    if (newset == NULL) {
+       xmlXPathFreeObject(set);
+        XP_ERROR(XPATH_MEMORY_ERROR);
+    }
     if (set->nodesetval == NULL) {
         goto error;
     }
@@ -2807,6 +2833,8 @@ xmlXPtrStringRangeFunction(xmlXPathParserContextPtr ctxt, int nargs) {
         */
        tmp = xmlXPtrNewLocationSetNodeSet(set->nodesetval);
        xmlXPathFreeObject(set);
+       if (tmp == NULL)
+            XP_ERROR(XPATH_MEMORY_ERROR)
        set = tmp;
     }
     oldset = (xmlLocationSetPtr) set->user;