lib-compression: gz compression didn't handle multiple flushes correctly.

diff --git a/src/lib-compression/ostream-zlib.c b/src/lib-compression/ostream-zlib.c
index 7472bbe6f09333be0ac27521443dde0d2aa85bb8..efc77e6cc789180eabed24cd3f61752026895198 100644 (file)
--- a/src/lib-compression/ostream-zlib.c
+++ b/src/lib-compression/ostream-zlib.c
@@ -141,12 +141,18 @@ o_stream_zlib_send_chunk(struct zlib_ostream *zstream,
                        }
                }
 
-               switch (deflate(zs, flush)) {
+               ret = deflate(zs, flush);
+               switch (ret) {
                case Z_OK:
                case Z_BUF_ERROR:
                        break;
+               case Z_STREAM_ERROR:
+                       i_assert(zstream->gz);
+                       i_panic("zlib.write(%s) failed: Can't write more data to .gz after flushing",
+                               o_stream_get_name(&zstream->ostream.ostream));
                default:
-                       i_unreached();
+                       i_panic("zlib.write(%s) failed with unexpected code %d",
+                               o_stream_get_name(&zstream->ostream.ostream), ret);
                }
        }
        size -= zs->avail_in;
@@ -158,12 +164,13 @@ o_stream_zlib_send_chunk(struct zlib_ostream *zstream,
        return size;
 }
 
-static int o_stream_zlib_send_flush(struct zlib_ostream *zstream)
+static int
+o_stream_zlib_send_flush(struct zlib_ostream *zstream, bool final)
 {
        z_stream *zs = &zstream->zs;
        unsigned int len;
        bool done = FALSE;
-       int ret;
+       int ret, flush;
 
        if (zs->avail_in != 0) {
                i_assert(zstream->ostream.ostream.last_failed_errno != 0);
@@ -182,6 +189,9 @@ static int o_stream_zlib_send_flush(struct zlib_ostream *zstream)
        if ((ret = o_stream_zlib_send_outbuf(zstream)) <= 0)
                return ret;
 
+       flush = !zstream->gz ? Z_SYNC_FLUSH :
+               (final ? Z_FINISH : Z_NO_FLUSH);
+
        i_assert(zstream->outbuf_used == 0);
        do {
                len = sizeof(zstream->outbuf) - zs->avail_out;
@@ -196,7 +206,7 @@ static int o_stream_zlib_send_flush(struct zlib_ostream *zstream)
                                break;
                }
 
-               switch (deflate(zs, zstream->gz ? Z_FINISH : Z_SYNC_FLUSH)) {
+               switch (deflate(zs, flush)) {
                case Z_OK:
                case Z_BUF_ERROR:
                        break;
@@ -208,9 +218,12 @@ static int o_stream_zlib_send_flush(struct zlib_ostream *zstream)
                }
        } while (zs->avail_out != sizeof(zstream->outbuf));
 
-       if (o_stream_zlib_send_gz_trailer(zstream) < 0)
-               return -1;
-       zstream->flushed = TRUE;
+       if (final) {
+               if (o_stream_zlib_send_gz_trailer(zstream) < 0)
+                       return -1;
+       }
+       if (final || flush != Z_NO_FLUSH)
+               zstream->flushed = TRUE;
        return 0;
 }
 
@@ -219,7 +232,7 @@ static int o_stream_zlib_flush(struct ostream_private *stream)
        struct zlib_ostream *zstream = (struct zlib_ostream *)stream;
        int ret;
 
-       if (o_stream_zlib_send_flush(zstream) < 0)
+       if (o_stream_zlib_send_flush(zstream, TRUE) < 0)
                return -1;
 
        ret = o_stream_flush(stream->parent);
@@ -254,7 +267,7 @@ o_stream_zlib_sendv(struct ostream_private *stream,
        stream->ostream.offset += bytes;
 
        if (!zstream->ostream.corked && i == iov_count) {
-               if (o_stream_zlib_send_flush(zstream) < 0)
+               if (o_stream_zlib_send_flush(zstream, FALSE) < 0)
                        return -1;
        }
        /* avail_in!=0 check is used to detect errors. if it's non-zero here