Inflate: use max window size by default, #174

lib/inflate.js

@@ -101,7 +101,7 @@ const {
 function Inflate(options) {
   this.options = utils.assign({
     chunkSize: 16384,
-    windowBits: 0,
+    windowBits: 15,
     to: ''
   }, options || {});
 

lib/zlib/inflate.js

@@ -471,7 +471,12 @@ const inflate = (strm, flush) => {
           state.mode = BAD;
           break;
         }
-        state.dmax = 1 << len;
+
+        // !!! pako patch. Force use `options.windowBits` if passed.
+        // Required to always use max window size by default.
+        state.dmax = 1 << state.wbits;
+        //state.dmax = 1 << len;
+
         //Tracev((stderr, "inflate:   zlib header ok\n"));
         strm.adler = state.check = 1/*adler32(0L, Z_NULL, 0)*/;
         state.mode = hold & 0x200 ? DICTID : TYPE;

test/inflate.js

@@ -3,6 +3,8 @@
 
 const zlib        = require('zlib');
 const assert      = require('assert');
+const fs      = require('fs');
+const path    = require('path');
 
 const pako        = require('../index');
 const { testInflate, testSamples, loadSamples } = require('./helpers');
@@ -206,3 +208,14 @@ describe('Inflate with dictionary', () => {
     testInflate(samples, { dictionary: dict.buffer }, { dictionary: dict });
   });
 });
+
+
+describe('pako patches for inflate', () => {
+
+  it('Force use max window size by default', () => {
+    const data = fs.readFileSync(path.join(__dirname, 'fixtures/bad_wbits.deflate'));
+    const unpacked = fs.readFileSync(path.join(__dirname, 'fixtures/bad_wbits.txt'));
+
+    assert.deepStrictEqual(pako.inflate(data), new Uint8Array(unpacked));
+  });
+});