message-decoder: Fixed assert-crash when trying to decode partial character twice.

diff --git a/src/lib-mail/message-decoder.c b/src/lib-mail/message-decoder.c
index c62fdf2e67937160a2fade8b6753abf4acd68e80..5645f3bc24805d4e2fb641d7874785888eeeda8b 100644 (file)
--- a/src/lib-mail/message-decoder.c
+++ b/src/lib-mail/message-decoder.c
@@ -207,7 +207,7 @@ static void translation_buf_decode(struct message_decoder_context *ctx,
 {
        unsigned char trans_buf[MAX_TRANSLATION_BUF_SIZE+1];
        unsigned int data_wanted, skip;
-       size_t trans_size;
+       size_t trans_size, orig_size;
 
        /* @UNSAFE: move the previously untranslated bytes to trans_buf
           and see if we have now enough data to get the next character
@@ -218,11 +218,19 @@ static void translation_buf_decode(struct message_decoder_context *ctx,
                data_wanted = *size;
        memcpy(trans_buf + ctx->translation_size, *data, data_wanted);
 
-       trans_size = ctx->translation_size + data_wanted;
+       orig_size = trans_size = ctx->translation_size + data_wanted;
        (void)charset_to_utf8(ctx->charset_trans, trans_buf,
                              &trans_size, ctx->buf2);
 
-       i_assert(trans_size > ctx->translation_size);
+       if (trans_size < ctx->translation_size) {
+               /* need more data to finish the translation. */
+               i_assert(orig_size < MAX_TRANSLATION_BUF_SIZE);
+               memcpy(ctx->translation_buf, trans_buf, orig_size);
+               ctx->translation_size = orig_size;
+               *data += *size;
+               *size = 0;
+               return;
+       }
        skip = trans_size - ctx->translation_size;
 
        i_assert(*size >= skip);