html: Avoid HTML_PARSE_HTML5 clashing with XML_PARSE_NOENT

There are several users that pass invalid XML parser options to the
HTML parser. Choose a value that is less likely to clash.

Author: nwellnhof

HTMLparser.c

@@ -5756,7 +5756,10 @@ htmlCtxtSetOptionsInternal(xmlParserCtxtPtr ctxt, int options, int keepMask)
 
     ctxt->linenumbers = 1;
 
-    return(options & ~allMask);
+    /*
+     * Allow XML_PARSE_NOENT which many users set on the HTML parser.
+     */
+    return(options & ~allMask & ~XML_PARSE_NOENT);
 }
 
 /**

include/libxml/HTMLparser.h

@@ -197,7 +197,6 @@ XMLPUBFUN void
  */
 typedef enum {
     HTML_PARSE_RECOVER  = 1<<0, /* No effect */
-    HTML_PARSE_HTML5    = 1<<1, /* HTML5 support */
     HTML_PARSE_NODEFDTD = 1<<2, /* do not default a doctype if not found */
     HTML_PARSE_NOERROR	= 1<<5,	/* suppress error reports */
     HTML_PARSE_NOWARNING= 1<<6,	/* suppress warning reports */
@@ -208,7 +207,8 @@ typedef enum {
     HTML_PARSE_COMPACT  = 1<<16,/* compact small text nodes */
     HTML_PARSE_HUGE     = 1<<19,/* relax any hardcoded limit from the parser */
     HTML_PARSE_IGNORE_ENC=1<<21,/* ignore internal document encoding hint */
-    HTML_PARSE_BIG_LINES= 1<<22 /* Store big lines numbers in text PSVI field */
+    HTML_PARSE_BIG_LINES= 1<<22,/* Store big lines numbers in text PSVI field */
+    HTML_PARSE_HTML5    = 1<<26 /* HTML5 support */
 } htmlParserOption;
 
 XMLPUBFUN void