From: Timo Sirainen <timo.sirainen@open-xchange.com>
Date: Tue, 9 Jun 2020 08:40:53 +0000 (+0300)
Subject: lib-compression: istream-zstd - Fix infinite loop when istream is nonblocking
X-Git-Tag: 2.3.13~515
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=0fb7f89740ef38d511ea8ef8ec48046296b08ac5;p=thirdparty%2Fdovecot%2Fcore.git

lib-compression: istream-zstd - Fix infinite loop when istream is nonblocking
---

diff --git a/src/lib-compression/istream-zstd.c b/src/lib-compression/istream-zstd.c
index d19594b19a..7f3d71cfd8 100644
--- a/src/lib-compression/istream-zstd.c
+++ b/src/lib-compression/istream-zstd.c
@@ -138,6 +138,8 @@ static ssize_t i_stream_zstd_read(struct istream_private *stream)
 					stream->istream.stream_errno = EPIPE;
 				return ret;
 			}
+			if (ret == 0)
+				return 0;
 			buffer_append(zstream->frame_buffer, data, size);
 			i_stream_skip(stream->parent, size);
 			zstream->input.src = zstream->frame_buffer->data;
@@ -145,6 +147,7 @@ static ssize_t i_stream_zstd_read(struct istream_private *stream)
 			zstream->input.pos = 0;
 		}
 
+		i_assert(zstream->input.size > 0);
 		i_assert(zstream->data_buffer->used == 0);
 		zstream->output.dst = buffer_append_space_unsafe(zstream->data_buffer,
 								 ZSTD_DStreamOutSize());