[libxml2] Stop checking attributes for UTF-8 validity

[Nick Wellnhofer <nwellnhof src gnome org>]

commit a6e6498fb1d11f08c394ecbf69add6cfff815db0
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Tue Mar 2 13:09:06 2021 +0100

    Stop checking attributes for UTF-8 validity
    
    I can't see a reason to check attribute content for UTF-8 validity.
    Other parts of the API like xmlNewText have always assumed valid UTF-8
    as extra checks only slow down processing.
    
    Besides, setting doc->encoding to "ISO-8859-1" seems pointless, and not
    freeing the old encoding would cause a memory leak.
    
    Note that this was last changed in 2008 with commit 6f8611fd which
    removed unnecessary encoding/decoding steps. Setting attributes should
    be even faster now.
    
    Found by OSS-Fuzz.

 tree.c | 12 ------------
 1 file changed, 12 deletions(-)
---
diff --git a/tree.c b/tree.c
index 617e8184..17db4452 100644
--- a/tree.c
+++ b/tree.c
@@ -1901,12 +1901,6 @@ xmlNewPropInternal(xmlNodePtr node, xmlNsPtr ns,
     if (value != NULL) {
         xmlNodePtr tmp;
 
-        if(!xmlCheckUTF8(value)) {
-            xmlTreeErr(XML_TREE_NOT_UTF8, (xmlNodePtr) doc,
-                       NULL);
-            if (doc != NULL)
-                doc->encoding = xmlStrdup(BAD_CAST "ISO-8859-1");
-        }
         cur->children = xmlNewDocText(doc, value);
         cur->last = NULL;
         tmp = cur->children;
@@ -6945,12 +6939,6 @@ xmlSetNsProp(xmlNodePtr node, xmlNsPtr ns, const xmlChar *name,
        if (value != NULL) {
            xmlNodePtr tmp;
 
-           if(!xmlCheckUTF8(value)) {
-               xmlTreeErr(XML_TREE_NOT_UTF8, (xmlNodePtr) node->doc,
-                          NULL);
-                if (node->doc != NULL)
-                    node->doc->encoding = xmlStrdup(BAD_CAST "ISO-8859-1");
-           }
            prop->children = xmlNewDocText(node->doc, value);
            prop->last = NULL;
            tmp = prop->children;