Fix error handling of deflate

1 files changed, 6 insertions, 5 deletions

diff --git a/src/cc4group.c b/src/cc4group.c
index 82e8df5..f040f23 100644
--- a/src/cc4group.c
+++ b/src/cc4group.c
@@ -1614,7 +1614,7 @@ static bool cc4group_deflateToCallback(WriteCallback* const callback, const void
 	callback->gzStream.next_in = (void*)data;
 	callback->gzStream.avail_in = size;
 
-	int ret = Z_OK;
+	int ret = Z_BUF_ERROR;
 
 	// skip the gzip magic if not done yet
 	if(!callback->magicDone)
@@ -1627,10 +1627,6 @@ static bool cc4group_deflateToCallback(WriteCallback* const callback, const void
 
 		ret = deflate(&callback->gzStream, Z_NO_FLUSH);
 	}
-	else if(size == 0)
-	{
-		ret = Z_BUF_ERROR;
-	}
 
 	while(ret == Z_BUF_ERROR || callback->gzStream.avail_in > 0)
 	{
@@ -1645,6 +1641,11 @@ static bool cc4group_deflateToCallback(WriteCallback* const callback, const void
 		{
 			cc4group_flushBufferedWrite(callback);
 		}
+
+		if(ret == Z_STREAM_ERROR)
+		{
+			return false;
+		}
 	}
 
 	assert(callback->gzStream.avail_in == 0);