zlib: fix windowBits validation to allow 0 for decompression mode

From the zlib v1.2.11 manual:

> ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
>                                      int  windowBits));
>
> ...
> windowBits can also be zero to request that inflate use the window
> size in the zlib header of the compressed stream.

The current validation of windowBits in zlib.js doesn't check for this
case.

PR-URL: https://github.com/nodejs/node/pull/19686
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

1 files changed, 33 insertions, 0 deletions

diff --git a/test/parallel/test-zlib-zero-windowBits.js b/test/parallel/test-zlib-zero-windowBits.js
new file mode 100644
index 0000000000..a62e6148e3
--- /dev/null
+++ b/test/parallel/test-zlib-zero-windowBits.js
@@ -0,0 +1,33 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+const zlib = require('zlib');
+
+
+// windowBits is a special case in zlib. On the compression side, 0 is invalid.
+// On the decompression side, it indicates that zlib should use the value from
+// the header of the compressed stream.
+{
+  const inflate = zlib.createInflate({ windowBits: 0 });
+  assert(inflate instanceof zlib.Inflate);
+}
+
+{
+  const gunzip = zlib.createGunzip({ windowBits: 0 });
+  assert(gunzip instanceof zlib.Gunzip);
+}
+
+{
+  const unzip = zlib.createUnzip({ windowBits: 0 });
+  assert(unzip instanceof zlib.Unzip);
+}
+
+{
+  common.expectsError(() => zlib.createGzip({ windowBits: 0 }), {
+    code: 'ERR_OUT_OF_RANGE',
+    type: RangeError,
+    message: 'The value of "options.windowBits" is out of range. ' +
+             'It must be >= 8 and <= 15. Received 0'
+  });
+}