[libxslt] Fix double-free with stylesheets containing entity nodes

[Nick Wellnhofer <nwellnhof src gnome org>]

commit 3e8bbcdec8d2318ca8ab27a2a4a509a5d9bb2d51
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Tue Feb 2 04:28:15 2021 +0100

    Fix double-free with stylesheets containing entity nodes
    
    Fix broken logic to make sure that entity nodes are deleted from the
    stylesheet. Note that stylesheets parsed with XML_PARSE_NOENT, which
    is included in XSLT_PARSE_OPTIONS, aren't affected.
    
    Found by OSS-Fuzz.

 libxslt/xslt.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)
---
diff --git a/libxslt/xslt.c b/libxslt/xslt.c
index 7a1ce011..69116f2b 100644
--- a/libxslt/xslt.c
+++ b/libxslt/xslt.c
@@ -3656,12 +3656,8 @@ xsltPreprocessStylesheet(xsltStylesheetPtr style, xmlNodePtr cur)
            (!xsltCheckExtURI(style, cur->ns->href))) {
            goto skip_children;
        } else if (cur->children != NULL) {
-           if ((cur->children->type != XML_ENTITY_DECL) &&
-               (cur->children->type != XML_ENTITY_REF_NODE) &&
-               (cur->children->type != XML_ENTITY_NODE)) {
-               cur = cur->children;
-               continue;
-           }
+           cur = cur->children;
+           continue;
        }
 
 skip_children: