[libxml2] Stop using doc->charset outside parser code

[Nick Wellnhofer <nwellnhof src gnome org>]

commit ee501f5449e14a25115a46e8bedec728ca00a89d
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Sat Oct 13 15:23:35 2018 +0200

    Stop using doc->charset outside parser code
    
    doc->charset does not specify the in-memory encoding which is always
    UTF-8.

 HTMLtree.c            | 38 ++++----------------------------------
 c14n.c                |  9 ---------
 include/libxml/tree.h |  2 +-
 xmlsave.c             |  3 ---
 4 files changed, 5 insertions(+), 47 deletions(-)
---
diff --git a/HTMLtree.c b/HTMLtree.c
index 2fd0c9c5..6a2f43d8 100644
--- a/HTMLtree.c
+++ b/HTMLtree.c
@@ -570,16 +570,7 @@ htmlDocDumpMemoryFormat(xmlDocPtr cur, xmlChar**mem, int *size, int format) {
        xmlCharEncoding enc;
 
        enc = xmlParseCharEncoding(encoding);
-       if (enc != cur->charset) {
-           if (cur->charset != XML_CHAR_ENCODING_UTF8) {
-               /*
-                * Not supported yet
-                */
-               *mem = NULL;
-               *size = 0;
-               return;
-           }
-
+       if (enc != XML_CHAR_ENCODING_UTF8) {
            handler = xmlFindCharEncodingHandler(encoding);
            if (handler == NULL)
                 htmlSaveErr(XML_SAVE_UNKNOWN_ENCODING, NULL, encoding);
@@ -1101,14 +1092,7 @@ htmlDocDump(FILE *f, xmlDocPtr cur) {
        xmlCharEncoding enc;
 
        enc = xmlParseCharEncoding(encoding);
-       if (enc != cur->charset) {
-           if (cur->charset != XML_CHAR_ENCODING_UTF8) {
-               /*
-                * Not supported yet
-                */
-               return(-1);
-           }
-
+       if (enc != XML_CHAR_ENCODING_UTF8) {
            handler = xmlFindCharEncodingHandler(encoding);
            if (handler == NULL)
                htmlSaveErr(XML_SAVE_UNKNOWN_ENCODING, NULL, encoding);
@@ -1160,14 +1144,7 @@ htmlSaveFile(const char *filename, xmlDocPtr cur) {
        xmlCharEncoding enc;
 
        enc = xmlParseCharEncoding(encoding);
-       if (enc != cur->charset) {
-           if (cur->charset != XML_CHAR_ENCODING_UTF8) {
-               /*
-                * Not supported yet
-                */
-               return(-1);
-           }
-
+       if (enc != XML_CHAR_ENCODING_UTF8) {
            handler = xmlFindCharEncodingHandler(encoding);
            if (handler == NULL)
                htmlSaveErr(XML_SAVE_UNKNOWN_ENCODING, NULL, encoding);
@@ -1221,14 +1198,7 @@ htmlSaveFileFormat(const char *filename, xmlDocPtr cur,
        xmlCharEncoding enc;
 
        enc = xmlParseCharEncoding(encoding);
-       if (enc != cur->charset) {
-           if (cur->charset != XML_CHAR_ENCODING_UTF8) {
-               /*
-                * Not supported yet
-                */
-               return(-1);
-           }
-
+       if (enc != XML_CHAR_ENCODING_UTF8) {
            handler = xmlFindCharEncodingHandler(encoding);
            if (handler == NULL)
                htmlSaveErr(XML_SAVE_UNKNOWN_ENCODING, NULL, encoding);
diff --git a/c14n.c b/c14n.c
index c04ce666..d80ae8b7 100644
--- a/c14n.c
+++ b/c14n.c
@@ -1797,15 +1797,6 @@ xmlC14NNewCtx(xmlDocPtr doc,
         return (NULL);
     }
 
-    /*
-     *  Validate the XML document encoding value, if provided.
-     */
-    if (doc->charset != XML_CHAR_ENCODING_UTF8) {
-        xmlC14NErr(ctx, (xmlNodePtr) doc, XML_C14N_REQUIRES_UTF8,
-                  "xmlC14NNewCtx: source document not in UTF8\n");
-        return (NULL);
-    }
-
     /*
      * Allocate a new xmlC14NCtxPtr and fill the fields.
      */
diff --git a/include/libxml/tree.h b/include/libxml/tree.h
index 4a9b3bc6..626ed6ae 100644
--- a/include/libxml/tree.h
+++ b/include/libxml/tree.h
@@ -575,7 +575,7 @@ struct _xmlDoc {
     void           *ids;        /* Hash table for ID attributes if any */
     void           *refs;       /* Hash table for IDREFs attributes if any */
     const xmlChar  *URL;       /* The URI for that document */
-    int             charset;    /* encoding of the in-memory content
+    int             charset;    /* Internal flag for charset handling,
                                   actually an xmlCharEncoding */
     struct _xmlDict *dict;      /* dict used to allocate names or NULL */
     void           *psvi;      /* for type/PSVI informations */
diff --git a/xmlsave.c b/xmlsave.c
index 6c7418ec..7a05d832 100644
--- a/xmlsave.c
+++ b/xmlsave.c
@@ -1123,9 +1123,6 @@ xmlDocContentDumpOutput(xmlSaveCtxtPtr ctxt, xmlDocPtr cur) {
         cur->encoding = BAD_CAST ctxt->encoding;
     } else if (cur->encoding != NULL) {
        encoding = cur->encoding;
-    } else if (cur->charset != XML_CHAR_ENCODING_UTF8) {
-       encoding = (const xmlChar *)
-                    xmlGetCharEncodingName((xmlCharEncoding) cur->charset);
     }
 
     if (((cur->type == XML_HTML_DOCUMENT_NODE) &&