Avoid call stack overflow with XML reader and recursive XIncludes
Don't process XIncludes in the result of another inclusion to avoid
infinite recursion resulting in a call stack overflow.
This is something the XInclude engine shouldn't allow but correct
handling of intra-document includes would require major changes.
Found by OSS-Fuzz.
diff --git a/xmlreader.c b/xmlreader.c
index 01adf74..72e40b0 100644
--- a/xmlreader.c
+++ b/xmlreader.c
@@ -1585,7 +1585,8 @@
/*
* Handle XInclude if asked for
*/
- if ((reader->xinclude) && (reader->node != NULL) &&
+ if ((reader->xinclude) && (reader->in_xinclude == 0) &&
+ (reader->node != NULL) &&
(reader->node->type == XML_ELEMENT_NODE) &&
(reader->node->ns != NULL) &&
((xmlStrEqual(reader->node->ns->href, XINCLUDE_NS)) ||
