When outputting HTML messages, check to see if there is a META tag in the HTML

that overrides the MIME content-type.  This is *not* legal MIME, but it seems to
be common practice in Asian messages so we have to deal with it.

diff --git a/webcit/html2html.c b/webcit/html2html.c
index 586f418424acdf18ed69a3b6725d72c8268672e7..00a2adcbb9301260c93462cac4515b6ea11dd3b2 100644 (file)
--- a/webcit/html2html.c
+++ b/webcit/html2html.c
@@ -12,12 +12,65 @@
 #include "webserver.h"
 
 
+/**
+ * \brief      Strip surrounding single or double quotes from a string.
+ *
+ * \param s    String to be stripped.
+ */
+void stripquotes(char *s)
+{
+       int len;
+
+       if (!s) return;
+
+       len = strlen(s);
+       if (len < 2) return;
+
+       if ( ( (s[0] == '\"') && (s[len-1] == '\"') ) || ( (s[0] == '\'') && (s[len-1] == '\'') ) ) {
+               s[len-1] = 0;
+               strcpy(s, &s[1]);
+       }
+}
+
+
+/**
+ * \brief Check to see if a META tag has overridden the declared MIME character set.
+ *
+ * \param charset              Character set name (left unchanged if we don't do anything)
+ * \param meta_http_equiv      Content of the "http-equiv" portion of the META tag
+ * \param meta_content         Content of the "content" portion of the META tag
+ */
+void extract_charset_from_meta(char *charset, char *meta_http_equiv, char *meta_content)
+{
+       char *ptr;
+       char buf[64];
+
+       if (!charset) return;
+       if (!meta_http_equiv) return;
+       if (!meta_content) return;
+
+
+       if (strcasecmp(meta_http_equiv, "Content-type")) return;
+
+       ptr = strchr(meta_content, ';');
+       if (!ptr) return;
+
+       safestrncpy(buf, ++ptr, sizeof buf);
+       striplt(buf);
+       if (!strncasecmp(buf, "charset=", 8)) {
+               strcpy(charset, &buf[8]);
+       }
+}
+
+
+
 /**
  * \brief Sanitize and enhance an HTML message for display.
- * Also convert weird character sets to UTF-8 if necessary.
- * \param charset the input charset
+ *        Also convert weird character sets to UTF-8 if necessary.
+ *
+ * \param supplied_charset the input charset as declared in the MIME headers
  */
-void output_html(char *charset, int treat_as_wiki) {
+void output_html(char *supplied_charset, int treat_as_wiki) {
        char buf[SIZ];
        char *msg;
        char *ptr;
@@ -33,6 +86,7 @@ void output_html(char *charset, int treat_as_wiki) {
        int alevel = 0;
        int i;
        int linklen;
+       char charset[128];
 #ifdef HAVE_ICONV
        iconv_t ic = (iconv_t)(-1) ;
        char *ibuf;                   /**< Buffer of characters to be converted */
@@ -42,6 +96,7 @@ void output_html(char *charset, int treat_as_wiki) {
        char *osav;                   /**< Saved pointer to output buffer       */
 #endif
 
+       safestrncpy(charset, supplied_charset, sizeof charset);
        msg = strdup("");
        sprintf(new_window, "<a target=\"%s\" href=", TARGET);
 
@@ -63,32 +118,7 @@ void output_html(char *charset, int treat_as_wiki) {
                content_length += 1;
        }
 
-#ifdef HAVE_ICONV
-       if ( (strcasecmp(charset, "us-ascii"))
-          && (strcasecmp(charset, "UTF-8"))
-          && (strcasecmp(charset, ""))
-       ) {
-               ic = iconv_open("UTF-8", charset);
-               if (ic == (iconv_t)(-1) ) {
-                       lprintf(5, "%s:%d iconv_open() failed: %s\n",
-                               __FILE__, __LINE__, strerror(errno));
-               }
-       }
-       if (ic != (iconv_t)(-1) ) {
-               ibuf = msg;
-               ibuflen = content_length;
-               obuflen = content_length + (content_length / 2) ;
-               obuf = (char *) malloc(obuflen);
-               osav = obuf;
-               iconv(ic, &ibuf, &ibuflen, &obuf, &obuflen);
-               content_length = content_length + (content_length / 2) - obuflen;
-               osav[content_length] = 0;
-               free(msg);
-               msg = osav;
-               iconv_close(ic);
-       }
-#endif
-
+       /** Do a first pass to isolate the message body */
        ptr = msg;
        msgstart = msg;
        msgend = &msg[content_length];
@@ -101,6 +131,51 @@ void output_html(char *charset, int treat_as_wiki) {
                ++ptr;
                if ((ptr == NULL) || (ptr >= msgend)) break;
 
+               /**
+                *  Look for META tags.  Some messages (particularly in
+                *  Asian locales) illegally declare a message's character
+                *  set in the HTML instead of in the MIME headers.  This
+                *  is wrong but we have to work around it anyway.
+                */
+               if (!strncasecmp(ptr, "META", 4)) {
+
+                       char *meta_start;
+                       char *meta_end;
+                       int meta_length;
+                       char *meta;
+                       char *meta_http_equiv;
+                       char *meta_content;
+                       char *spaceptr;
+
+                       meta_start = &ptr[4];
+                       meta_end = strchr(ptr, '>');
+                       if ((meta_end != NULL) && (meta_end <= msgend)) {
+                               meta_length = meta_end - meta_start + 1;
+                               meta = malloc(meta_length + 1);
+                               safestrncpy(meta, meta_start, meta_length);
+                               meta[meta_length] = 0;
+                               striplt(meta);
+                               if (!strncasecmp(meta, "HTTP-EQUIV=", 11)) {
+                                       meta_http_equiv = strdup(&meta[11]);
+                                       spaceptr = strchr(meta_http_equiv, ' ');
+                                       if (spaceptr != NULL) {
+                                               *spaceptr = 0;
+                                               meta_content = strdup(++spaceptr);
+                                               if (!strncasecmp(meta_content, "content=", 8)) {
+                                                       strcpy(meta_content, &meta_content[8]);
+                                                       stripquotes(meta_http_equiv);
+                                                       stripquotes(meta_content);
+                                                       extract_charset_from_meta(charset,
+                                                               meta_http_equiv, meta_content);
+                                               }
+                                               free(meta_content);
+                                       }
+                                       free(meta_http_equiv);
+                               }
+                               free(meta);
+                       }
+               }
+
                /**
                 * Any of these tags cause everything up to and including
                 * the tag to be removed.
@@ -130,7 +205,43 @@ void output_html(char *charset, int treat_as_wiki) {
 
                ++ptr;
        }
+       if (msgstart > msg) {
+               strcpy(msg, msgstart);
+       }
+
+       /** Convert foreign character sets to UTF-8 if necessary. */
+#ifdef HAVE_ICONV
+       if ( (strcasecmp(charset, "us-ascii"))
+          && (strcasecmp(charset, "UTF-8"))
+          && (strcasecmp(charset, ""))
+       ) {
+               lprintf(9, "Converting %s to UTF-8\n", charset);
+               ic = iconv_open("UTF-8", charset);
+               if (ic == (iconv_t)(-1) ) {
+                       lprintf(5, "%s:%d iconv_open() failed: %s\n",
+                               __FILE__, __LINE__, strerror(errno));
+               }
+       }
+       if (ic != (iconv_t)(-1) ) {
+               ibuf = msg;
+               ibuflen = content_length;
+               obuflen = content_length + (content_length / 2) ;
+               obuf = (char *) malloc(obuflen);
+               osav = obuf;
+               iconv(ic, &ibuf, &ibuflen, &obuf, &obuflen);
+               content_length = content_length + (content_length / 2) - obuflen;
+               osav[content_length] = 0;
+               free(msg);
+               msg = osav;
+               iconv_close(ic);
+       }
+#endif
+
+       /** FIXME At this point, shigerugo's messages are still clean.
+        *        Figure out what is mangling them below.
+        */
 
+       /** Now go through the message, parsing tags as necessary. */
        converted_msg = malloc(content_length);
        strcpy(converted_msg, "");
        ptr = msgstart;