Defend against null error message reported by libxml2.

tglsfdc · tglsfdc · commit 0edef16d76be · 2019-02-08T13:30:42.000-05:00
While this isn't really supposed to happen, it can occur in OOM situations and perhaps others. Instead of crashing, substitute "(no message provided)". I didn't worry about localizing this text, since we aren't localizing anything else here; besides, if we're on the edge of OOM, it's unlikely gettext() would work. Report and fix by Sergio Conde Gómez in bug #15624. Discussion: https://postgr.es/m/15624-4dea54091a2864e6@postgresql.org
diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
@@ -1697,7 +1697,10 @@ xml_errorHandler(void *data, xmlErrorPtr error)
 		appendStringInfo(errorBuf, "line %d: ", error->line);
 	if (name != NULL)
 		appendStringInfo(errorBuf, "element %s: ", name);
-	appendStringInfoString(errorBuf, error->message);
+	if (error->message != NULL)
+		appendStringInfoString(errorBuf, error->message);
+	else
+		appendStringInfoString(errorBuf, "(no message provided)");
 
 	/*
 	 * Append context information to errorBuf.
