use iconv to convert RFC-2047 encoded headers to the character set used

[mmh] / sbr / fmt_rfc2047.c

diff --git a/sbr/fmt_rfc2047.c b/sbr/fmt_rfc2047.c
index b4bf4eb..a87fc0e 100644 (file)
--- a/sbr/fmt_rfc2047.c
+++ b/sbr/fmt_rfc2047.c
@@ -10,6 +10,10 @@
  */
 
 #include <h/mh.h>
+#ifdef HAVE_ICONV
+#  include <iconv.h>
+#  include <errno.h>
+#endif
 
 static signed char hexindex[] = {
     -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
@@ -61,6 +65,12 @@ decode_rfc2047 (char *str, char *dst)
     int between_encodings = 0; /* are we between two encodings?          */
     int equals_pending = 0;    /* is there a '=' pending?                */
     int whitespace = 0;                /* how much whitespace between encodings? */
+#ifdef HAVE_ICONV
+    int use_iconv = 0;          /* are we converting encoding with iconv? */
+    iconv_t cd;
+    int fromutf8;
+    char *saveq, *convbuf;
+#endif
 
     if (!str)
        return 0;
@@ -73,6 +83,14 @@ decode_rfc2047 (char *str, char *dst)
        return 0;
 
     for (p = str, q = dst; *p; p++) {
+
+        /* reset iconv */
+#ifdef HAVE_ICONV
+        if (use_iconv) {
+           iconv_close(cd);
+           use_iconv = 0;
+        }
+#endif
        /*
         * If we had an '=' character pending from
         * last iteration, then add it first.
@@ -106,9 +124,20 @@ decode_rfc2047 (char *str, char *dst)
            if (!*pp)
                continue;
 
-           /* Check if character set is OK */
-           if (!check_charset(startofmime, pp - startofmime))
+           /* Check if character set can be handled natively */
+           if (!check_charset(startofmime, pp - startofmime)) {
+#ifdef HAVE_ICONV
+               /* .. it can't. We'll use iconv then. */
+               *pp = '\0';
+               cd = iconv_open(get_charset(), startofmime);
+               fromutf8 = !strcasecmp(startofmime, "UTF-8");
+               *pp = '?';
+                if (cd == (iconv_t)-1) continue;
+               use_iconv = 1;
+#else
                continue;
+#endif
+           }
 
            startofmime = pp + 1;
 
@@ -159,6 +188,14 @@ decode_rfc2047 (char *str, char *dst)
            if (between_encodings)
                q -= whitespace;
 
+#ifdef HAVE_ICONV
+           if (use_iconv) {
+               saveq = q;
+               if (!(q = convbuf = (char *)malloc(endofmime - startofmime)))
+                   continue;
+            }
+#endif
+
            /* Now decode the text */
            if (quoted_printable) {
                for (pp = startofmime; pp < endofmime; pp++) {
@@ -218,6 +255,35 @@ decode_rfc2047 (char *str, char *dst)
                }
            }
 
+#ifdef HAVE_ICONV
+            /* Convert to native character set */
+           if (use_iconv) {
+               size_t inbytes = q - convbuf;
+               size_t outbytes = BUFSIZ;
+               ICONV_CONST char *start = convbuf;
+               
+               while (inbytes) {
+                   if (iconv(cd, &start, &inbytes, &saveq, &outbytes) ==
+                           (size_t)-1) {
+                       if (errno != EILSEQ) break;
+                       /* character couldn't be converted. we output a `?'
+                        * and try to carry on which won't work if
+                        * either encoding was stateful */
+                       iconv (cd, 0, 0, &saveq, &outbytes);
+                       *saveq++ = '?';
+                        /* skip to next input character */
+                       if (fromutf8) {
+                           for (start++;(*start & 192) == 128;start++)
+                               inbytes--;
+                       } else
+                           start++, inbytes--;
+                   }
+               }
+               q = saveq;
+               free(convbuf);
+           }
+#endif
+           
            /*
             * Now that we are done decoding this particular
             * encoded word, advance string to trailing '='.
@@ -229,6 +295,9 @@ decode_rfc2047 (char *str, char *dst)
            whitespace = 0;             /* re-initialize amount of whitespace */
        }
     }
+#ifdef HAVE_ICONV
+    if (use_iconv) iconv_close(cd);
+#endif
 
     /* If an equals was pending at end of string, add it now. */
     if (equals_pending)