More aggressive resets of state in xerial reader (segmentio#322)

In cases where the xerial reader requires more bytes than available in the decompressed buffer, we currently get corrupt data. That would result in the reader halting. Clearing out x.output and x.header ensures that this condition is handled gracefully.
ravi4422 · Jul 23, 2019 · 1248320 · 1248320
1 parent c98551b
commit 1248320
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/snappy/xerial.go b/snappy/xerial.go
@@ -27,6 +27,7 @@ func (x *xerialReader) Reset(r io.Reader) {
 	x.reader = r
 	x.input = x.input[:0]
 	x.output = x.output[:0]
+	x.header = [16]byte{}
 	x.offset = 0
 	x.nbytes = 0
 }
@@ -72,6 +73,7 @@ func (x *xerialReader) WriteTo(w io.Writer) (int64, error) {
 }
 
 func (x *xerialReader) readChunk(dst []byte) (int, error) {
+	x.output = x.output[:0]
 	x.offset = 0
 	prefix := 0