[Fix] Deal with 7bit charsets properly

Issue: #1651

diff --git a/src/libmime/mime_encoding.c b/src/libmime/mime_encoding.c
index ca02cbf2f4978de353106c5e528692d09086750a..c8c56b3547412f74f95e989e9d18763304a76b52 100644 (file)
--- a/src/libmime/mime_encoding.c
+++ b/src/libmime/mime_encoding.c
@@ -461,8 +461,8 @@ rspamd_mime_text_part_maybe_convert (struct rspamd_task *task,
 {
        GError *err = NULL;
        gsize write_bytes;
-       const gchar *charset;
-       gboolean checked = FALSE;
+       const gchar *charset = NULL;
+       gboolean checked = FALSE, need_charset_heuristic = TRUE;
        gchar *res_str;
        GByteArray *result_array, *part_content;
        rspamd_ftok_t charset_tok;
@@ -483,26 +483,31 @@ rspamd_mime_text_part_maybe_convert (struct rspamd_task *task,
        }
 
        if (!(text_part->flags & RSPAMD_MIME_TEXT_PART_FLAG_8BIT_ENCODED)) {
-               /* We don't care anymore about encoding */
-               SET_PART_UTF (text_part);
-
-               return part_content;
+               need_charset_heuristic = FALSE;
        }
 
        if (task->cfg && task->cfg->raw_mode) {
                SET_PART_RAW (text_part);
+
                return part_content;
        }
 
        if (part->ct->charset.len == 0) {
-               charset = rspamd_mime_charset_find_by_content (part_content->data,
-                               MIN (RSPAMD_CHARSET_MAX_CONTENT, part_content->len));
+               if (need_charset_heuristic) {
+                       charset = rspamd_mime_charset_find_by_content (part_content->data,
+                                       MIN (RSPAMD_CHARSET_MAX_CONTENT, part_content->len));
 
-               if (charset != NULL) {
-                       msg_info_task ("detected charset %s", charset);
+                       if (charset != NULL) {
+                               msg_info_task ("detected charset %s", charset);
+                       }
+
+                       checked = TRUE;
                }
+               else {
+                       SET_PART_UTF (text_part);
 
-               checked = TRUE;
+                       return part_content;
+               }
        }
        else {
                charset = rspamd_mime_detect_charset (&part->ct->charset,