zlib: report premature ends earlier

Report end-of-stream when decompressing when we detect it,
and do not wait until the writable side of a zlib stream
is closed as well.

Refs: https://github.com/nodejs/node/issues/26332

PR-URL: https://github.com/nodejs/node/pull/26363
Refs: https://github.com/nodejs/node/issues/26332
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: James M Snell <jasnell@gmail.com>

1 files changed, 33 insertions, 0 deletions

diff --git a/test/parallel/test-zlib-premature-end.js b/test/parallel/test-zlib-premature-end.js
new file mode 100644
index 0000000000..9e191c4c88
--- /dev/null
+++ b/test/parallel/test-zlib-premature-end.js
@@ -0,0 +1,33 @@
+'use strict';
+const common = require('../common');
+const zlib = require('zlib');
+const assert = require('assert');
+
+const input = '0123456789'.repeat(4);
+
+for (const [ compress, decompressor ] of [
+  [ zlib.deflateRawSync, zlib.createInflateRaw ],
+  [ zlib.deflateSync, zlib.createInflate ],
+  [ zlib.brotliCompressSync, zlib.createBrotliDecompress ]
+]) {
+  const compressed = compress(input);
+  const trailingData = Buffer.from('not valid compressed data');
+
+  for (const variant of [
+    (stream) => { stream.end(compressed); },
+    (stream) => { stream.write(compressed); stream.write(trailingData); },
+    (stream) => { stream.write(compressed); stream.end(trailingData); },
+    (stream) => { stream.write(Buffer.concat([compressed, trailingData])); },
+    (stream) => { stream.end(Buffer.concat([compressed, trailingData])); }
+  ]) {
+    let output = '';
+    const stream = decompressor();
+    stream.setEncoding('utf8');
+    stream.on('data', (chunk) => output += chunk);
+    stream.on('end', common.mustCall(() => {
+      assert.strictEqual(output, input);
+      assert.strictEqual(stream.bytesWritten, compressed.length);
+    }));
+    variant(stream);
+  }
+}