[libxml2] Add options to ignore the internal encoding

[Daniel Veillard <veillard src gnome org>]

commit c62efc847c836d4c4f1aea08c68cd93bd342b9f4
Author: Daniel Veillard <veillard redhat com>
Date:   Mon May 16 16:03:50 2011 +0800

    Add options to ignore the internal encoding
    
    For both XML and HTML, the document can provide an encoding
    either in XMLDecl in XML, or as a meta element in HTML head.
    This adds options to ignore those encodings if the encoding
    is known in advace for example if the content had been converted
    before being passed to the parser.
    
    * parser.c include/libxml/parser.h: add XML_PARSE_IGNORE_ENC option
      for XML parsing
    * include/libxml/HTMLparser.h HTMLparser.c: adds the
      HTML_PARSE_IGNORE_ENC for HTML parsing
    * HTMLtree.c: fix the handling of saving when an unknown encoding is
      defined in meta document header
    * xmllint.c: add a --noenc option to activate the new parser options

 HTMLparser.c                |   11 +++++++++--
 HTMLtree.c                  |   18 ++++++++----------
 include/libxml/HTMLparser.h |    3 ++-
 include/libxml/parser.h     |    5 +++--
 parser.c                    |   11 +++++++++++
 xmllint.c                   |    6 ++++++
 6 files changed, 39 insertions(+), 15 deletions(-)
---
diff --git a/HTMLparser.c b/HTMLparser.c
index 4d43b93..1a4d80d 100644
--- a/HTMLparser.c
+++ b/HTMLparser.c
@@ -3448,7 +3448,8 @@ static void
 htmlCheckEncoding(htmlParserCtxtPtr ctxt, const xmlChar *attvalue) {
     const xmlChar *encoding;
 
-    if ((ctxt == NULL) || (attvalue == NULL))
+    if ((ctxt == NULL) || (attvalue == NULL) ||
+        (ctxt->options & HTML_PARSE_IGNORE_ENC))
 	return;
 
     /* do not change encoding */
@@ -3500,7 +3501,9 @@ htmlCheckEncoding(htmlParserCtxtPtr ctxt, const xmlChar *attvalue) {
 		xmlSwitchToEncoding(ctxt, handler);
 		ctxt->charset = XML_CHAR_ENCODING_UTF8;
 	    } else {
-		ctxt->errNo = XML_ERR_UNSUPPORTED_ENCODING;
+		htmlParseErr(ctxt, XML_ERR_UNSUPPORTED_ENCODING,
+		             "htmlCheckEncoding: unknown encoding %s\n",
+			     encoding, NULL);
 	    }
 	}
 
@@ -6537,6 +6540,10 @@ htmlCtxtUseOptions(htmlParserCtxtPtr ctxt, int options)
 	ctxt->options |= HTML_PARSE_NODEFDTD;
         options -= HTML_PARSE_NODEFDTD;
     }
+    if (options & HTML_PARSE_IGNORE_ENC) {
+	ctxt->options |= HTML_PARSE_IGNORE_ENC;
+        options -= HTML_PARSE_IGNORE_ENC;
+    }
     ctxt->dictNames = 0;
     return (options);
 }
diff --git a/HTMLtree.c b/HTMLtree.c
index b508583..f23ae02 100644
--- a/HTMLtree.c
+++ b/HTMLtree.c
@@ -481,7 +481,7 @@ htmlNodeDumpFileFormat(FILE *out, xmlDocPtr doc,
 	if (enc != XML_CHAR_ENCODING_UTF8) {
 	    handler = xmlFindCharEncodingHandler(encoding);
 	    if (handler == NULL)
-		return(-1);
+		htmlSaveErr(XML_SAVE_UNKNOWN_ENCODING, NULL, encoding);
 	}
     }
 
@@ -562,11 +562,9 @@ htmlDocDumpMemoryFormat(xmlDocPtr cur, xmlChar**mem, int *size, int format) {
 	    }
 
 	    handler = xmlFindCharEncodingHandler(encoding);
-	    if (handler == NULL) {
-		*mem = NULL;
-		*size = 0;
-		return;
-	    }
+	    if (handler == NULL)
+                htmlSaveErr(XML_SAVE_UNKNOWN_ENCODING, NULL, encoding);
+
 	} else {
 	    handler = xmlFindCharEncodingHandler(encoding);
 	}
@@ -587,7 +585,7 @@ htmlDocDumpMemoryFormat(xmlDocPtr cur, xmlChar**mem, int *size, int format) {
 	return;
     }
 
-	htmlDocContentDumpFormatOutput(buf, cur, NULL, format);
+    htmlDocContentDumpFormatOutput(buf, cur, NULL, format);
 
     xmlOutputBufferFlush(buf);
     if (buf->conv != NULL) {
@@ -1061,7 +1059,7 @@ htmlDocDump(FILE *f, xmlDocPtr cur) {
 
 	    handler = xmlFindCharEncodingHandler(encoding);
 	    if (handler == NULL)
-		return(-1);
+		htmlSaveErr(XML_SAVE_UNKNOWN_ENCODING, NULL, encoding);
 	} else {
 	    handler = xmlFindCharEncodingHandler(encoding);
 	}
@@ -1120,7 +1118,7 @@ htmlSaveFile(const char *filename, xmlDocPtr cur) {
 
 	    handler = xmlFindCharEncodingHandler(encoding);
 	    if (handler == NULL)
-		return(-1);
+		htmlSaveErr(XML_SAVE_UNKNOWN_ENCODING, NULL, encoding);
 	}
     }
 
@@ -1181,7 +1179,7 @@ htmlSaveFileFormat(const char *filename, xmlDocPtr cur,
 
 	    handler = xmlFindCharEncodingHandler(encoding);
 	    if (handler == NULL)
-		return(-1);
+		htmlSaveErr(XML_SAVE_UNKNOWN_ENCODING, NULL, encoding);
 	}
         htmlSetMetaEncoding(cur, (const xmlChar *) encoding);
     } else {
diff --git a/include/libxml/HTMLparser.h b/include/libxml/HTMLparser.h
index fbcc811..10a3d65 100644
--- a/include/libxml/HTMLparser.h
+++ b/include/libxml/HTMLparser.h
@@ -184,7 +184,8 @@ typedef enum {
     HTML_PARSE_NOBLANKS	= 1<<8,	/* remove blank nodes */
     HTML_PARSE_NONET	= 1<<11,/* Forbid network access */
     HTML_PARSE_NOIMPLIED= 1<<13,/* Do not add implied html/body... elements */
-    HTML_PARSE_COMPACT  = 1<<16 /* compact small text nodes */
+    HTML_PARSE_COMPACT  = 1<<16,/* compact small text nodes */
+    HTML_PARSE_IGNORE_ENC=1<<21 /* ignore internal document encoding hint */
 } htmlParserOption;
 
 XMLPUBFUN void XMLCALL
diff --git a/include/libxml/parser.h b/include/libxml/parser.h
index 47b3df1..aabb96c 100644
--- a/include/libxml/parser.h
+++ b/include/libxml/parser.h
@@ -1105,8 +1105,9 @@ typedef enum {
 				   crash if you try to modify the tree) */
     XML_PARSE_OLD10	= 1<<17,/* parse using XML-1.0 before update 5 */
     XML_PARSE_NOBASEFIX = 1<<18,/* do not fixup XINCLUDE xml:base uris */
-    XML_PARSE_HUGE      = 1<<19, /* relax any hardcoded limit from the parser */
-    XML_PARSE_OLDSAX    = 1<<20 /* parse using SAX2 interface from before 2.7.0 */
+    XML_PARSE_HUGE      = 1<<19,/* relax any hardcoded limit from the parser */
+    XML_PARSE_OLDSAX    = 1<<20,/* parse using SAX2 interface before 2.7.0 */
+    XML_PARSE_IGNORE_ENC= 1<<21 /* ignore internal document encoding hint */
 } xmlParserOption;
 
 XMLPUBFUN void XMLCALL
diff --git a/parser.c b/parser.c
index 9ab8641..02a1877 100644
--- a/parser.c
+++ b/parser.c
@@ -9922,6 +9922,13 @@ xmlParseEncodingDecl(xmlParserCtxtPtr ctxt) {
 	} else {
 	    xmlFatalErr(ctxt, XML_ERR_STRING_NOT_STARTED, NULL);
 	}
+
+        /*
+         * Non standard parsing, allowing the user to ignore encoding
+         */
+        if (ctxt->options & XML_PARSE_IGNORE_ENC)
+            return(encoding);
+
 	/*
 	 * UTF-16 encoding stwich has already taken place at this stage,
 	 * more over the little-endian/big-endian selection is already done
@@ -14561,6 +14568,10 @@ xmlCtxtUseOptionsInternal(xmlParserCtxtPtr ctxt, int options, const char *encodi
 	ctxt->options |= XML_PARSE_OLDSAX;
         options -= XML_PARSE_OLDSAX;
     }
+    if (options & XML_PARSE_IGNORE_ENC) {
+	ctxt->options |= XML_PARSE_IGNORE_ENC;
+        options -= XML_PARSE_IGNORE_ENC;
+    }
     ctxt->linenumbers = 1;
     return (options);
 }
diff --git a/xmllint.c b/xmllint.c
index 8af56cd..14c64be 100644
--- a/xmllint.c
+++ b/xmllint.c
@@ -130,6 +130,7 @@ static int copy = 0;
 #endif /* LIBXML_TREE_ENABLED */
 static int recovery = 0;
 static int noent = 0;
+static int noenc = 0;
 static int noblanks = 0;
 static int noout = 0;
 static int nowrap = 0;
@@ -2983,6 +2984,7 @@ static void usage(const char *name) {
     printf("\t--recover : output what was parsable on broken XML documents\n");
     printf("\t--huge : remove any internal arbitrary parser limits\n");
     printf("\t--noent : substitute entity references by their value\n");
+    printf("\t--noenc : ignore any encoding specified inside the document\n");
     printf("\t--noout : don't output the result tree\n");
     printf("\t--path 'paths': provide a set of paths for resources\n");
     printf("\t--load-trace : print trace of all external entites loaded\n");
@@ -3137,6 +3139,10 @@ main(int argc, char **argv) {
 	         (!strcmp(argv[i], "--noent"))) {
 	    noent++;
 	    options |= XML_PARSE_NOENT;
+	} else if ((!strcmp(argv[i], "-noenc")) ||
+	         (!strcmp(argv[i], "--noenc"))) {
+	    noenc++;
+	    options |= XML_PARSE_IGNORE_ENC;
 	} else if ((!strcmp(argv[i], "-nsclean")) ||
 	         (!strcmp(argv[i], "--nsclean"))) {
 	    options |= XML_PARSE_NSCLEAN;