CVE-2015-5312 Another entity expansion issue

For https://bugzilla.gnome.org/show_bug.cgi?id=756733
It is one case where the code in place to detect entities expansions
failed to exit when the situation was detected, leading to DoS
Problem reported by Kostya Serebryany @ Google
Patch provided by David Drysdale @ Google
diff --git a/parser.c b/parser.c
index b7b6668..da6e729 100644
--- a/parser.c
+++ b/parser.c
@@ -2806,6 +2806,10 @@
 			                      0, 0, 0);
 		ctxt->depth--;
 
+		if ((ctxt->lastError.code == XML_ERR_ENTITY_LOOP) ||
+		    (ctxt->lastError.code == XML_ERR_INTERNAL_ERROR))
+		    goto int_error;
+
 		if (rep != NULL) {
 		    current = rep;
 		    while (*current != 0) { /* non input consuming loop */