Roll libxml to 3169602058bd2d04913909e869c61d1540bc7fb4

third_party/libxml/src/xpath.c

Index: third_party/libxml/src/xpath.c
diff --git a/third_party/libxml/src/xpath.c b/third_party/libxml/src/xpath.c
index a0d993a1fb5087184a911dafcada604b365865bb..7c24a824ec0c48a3b95f965150c9f6fa688a56aa 100644
--- a/third_party/libxml/src/xpath.c
+++ b/third_party/libxml/src/xpath.c
@@ -14008,9 +14008,14 @@ xmlXPathCompOpEval(xmlXPathParserContextPtr ctxt, xmlXPathStepOpPtr op)
                 xmlNodeSetPtr oldset;
                 int i, j;
 
-                if (op->ch1 != -1)
+                if (op->ch1 != -1) {
                     total +=
                         xmlXPathCompOpEval(ctxt, &comp->steps[op->ch1]);
+                    CHECK_ERROR0;
+                }
+                if (ctxt->value == NULL) {
+                    XP_ERROR0(XPATH_INVALID_OPERAND);
+                }
                 if (op->ch2 == -1)
                     return (total);