> On July 5, 2017 at 9:24 PM Anton Yuzhaninov <cit...@citrin.ru> wrote: > > > On 07/05/17 13:25, Aki Tuomi wrote: > >> I use mbox compressed by gzip as read-only folder (using zlib plugin). > >> > >> I have errors in logs: > >> Panic: file istream-zlib.c: line 416 (i_stream_zlib_seek): assertion > >> failed: (ret == -1) > ... > >> The bug appeared in 2.2.26 and still can be reproduced (in 2.2.31) > >> > >> Using 'git bisect' was not productive (a lot of build errors), but I've > >> found that reverting this commit: > >> https://github.com/dovecot/core/commit/6a1110d8757bb72fd90f4fe0857fd3aeaf8920ff > >> > >> "fixes" problem for me, so I suppose the bug was introduced in this commit. > > > If you only revert the bit here > > > > > > - } while (i_stream_read(&stream->istream) > 0); > > + } while ((ret = i_stream_read(&stream->istream)) > 0); > > > > in src/lib-compression/istream-zlib.c > > > > does it still fix the issue? > > With this change applied to fresh origin/master-2.2 I see no error: > --- a/src/lib-compression/istream-zlib.c > +++ b/src/lib-compression/istream-zlib.c > @@ -417,7 +417,7 @@ i_stream_zlib_seek(struct istream_private *stream, > uoff_t v_offset, bool mark) > } > > i_stream_skip(&stream->istream, avail); > - } while ((ret = i_stream_read(&stream->istream)) > 0); > + } while (i_stream_read(&stream->istream) > 0); > i_assert(ret == -1); > > if (stream->istream.v_offset != v_offset) { > > But if ret is not assigned, then assert below is useless. > > May be better fix will be: > index f7354d83d..06389362a 100644 > --- a/src/lib-compression/istream-zlib.c > +++ b/src/lib-compression/istream-zlib.c > @@ -404,7 +404,7 @@ i_stream_zlib_seek(struct istream_private *stream, > uoff_t v_offset, bool mark) > stream->pos = stream->skip; > } else { > /* read and cache forward */ > - ssize_t ret = -1; > + ssize_t ret; > > do { > size_t avail = stream->pos - stream->skip; > @@ -413,6 +413,7 @@ i_stream_zlib_seek(struct istream_private *stream, > uoff_t v_offset, bool mark) > i_stream_skip(&stream->istream, > v_offset - > stream->istream.v_offset); > + ret = -1; > break; > } > > It also works for me. > > Also similar code can be found in files for other compression formats.
Question is though, is the original code returning ret = -2? Is it possible for you find out? Aki
