fix: CRC is unexpectedly changed after zip is re-created

Author: teppeis

Diff for: .gitignore

@@ -1,4 +1,5 @@
-node_modules/
-test/issue_*/unzipped/
+node_modules
+/test/issue_*/unzipped/
+xxx
 .idea
-*.iml
+*.iml

Diff for: headers/entryHeader.js

@@ -213,7 +213,7 @@ module.exports = function () {
             // modification time (2 bytes time, 2 bytes date)
             data.writeUInt32LE(_time, Constants.CENTIM);
             // uncompressed file crc-32 value
-            data.writeInt32LE(_crc & 0xFFFF, Constants.CENCRC, true);
+            data.writeUInt32LE(_crc, Constants.CENCRC);
             // compressed size
             data.writeUInt32LE(_compressedSize, Constants.CENSIZ);
             // uncompressed size

Diff for: package.json

@@ -3,7 +3,7 @@
   "version": "0.4.12",
   "description": "Javascript implementation of zip for nodejs with support for electron original-fs. Allows user to create or extract zip files both in memory or to/from disk",
   "scripts": {
-    "test": "mocha test/mocha.js"
+    "test": "mocha test/mocha.js test/crc/index.js"
   },
   "keywords": [
     "zip",

Diff for: test/crc/index.js

@@ -1,44 +1,57 @@
-;(function () {
-    var assert = require('assert');
-    var path = require('path');
-    var Zip = require('../../adm-zip');
-
-    testGoodCrc();
-    testBadCrc();
-
-    // Good CRC
-    function testGoodCrc() {
-        var goodZip = new Zip(path.join(__dirname, 'good_crc.zip'));
-        var entries = goodZip.getEntries();
+const assert = require('assert');
+const path = require('path');
+const Zip = require('../../adm-zip');
+const rimraf = require('rimraf')
+
+describe('crc', () => {
+    const destination = __dirname + '/xxx'
+
+    beforeEach(done => rimraf(destination, done))
+
+    it('Good CRC', (done) => {
+        const goodZip = new Zip(path.join(__dirname, 'good_crc.zip'));
+        const entries = goodZip.getEntries();
         assert(entries.length === 1, 'Good CRC: Test archive contains exactly 1 file');
 
-        var testFile = entries.filter(function (entry) {
+        const testFile = entries.filter(function (entry) {
             return entry.entryName === 'lorem_ipsum.txt';
         });
         assert(testFile.length === 1, 'Good CRC: lorem_ipsum.txt file exists as archive entry');
 
-        var testFileEntryName = testFile[0].entryName;
+        const testFileEntryName = testFile[0].entryName;
         goodZip.readAsTextAsync(testFileEntryName, function (data, err) {
             assert(!err, 'Good CRC: error object not present');
             assert(data && data.length, 'Good CRC: buffer not empty');
+            done();
         });
-    }
+    });
 
-    // Bad CRC
-    function testBadCrc() {
-        var badZip = new Zip(path.join(__dirname, 'bad_crc.zip'));
-        var entries = badZip.getEntries();
+    it('Bad CRC', (done) => {
+        const badZip = new Zip(path.join(__dirname, 'bad_crc.zip'));
+        const entries = badZip.getEntries();
         assert(entries.length === 1, 'Bad CRC: Test archive contains exactly 1 file');
 
-        var testFile = entries.filter(function (entry) {
+        const testFile = entries.filter(function (entry) {
             return entry.entryName === 'lorem_ipsum.txt';
         });
         assert(testFile.length === 1, 'Bad CRC: lorem_ipsum.txt file exists as archive entry');
 
-        var testFileEntryName = testFile[0].entryName;
+        const testFileEntryName = testFile[0].entryName;
         badZip.readAsTextAsync(testFileEntryName, function (data, err) {
             assert(data && data.length, 'Bad CRC: buffer not empty');
             assert(err, 'Bad CRC: error object present');
+            done();
         });
-    }
-})();
+    });
+
+    it('CRC is not changed after re-created', () => {
+        const goodZip = new Zip(path.join(__dirname, 'good_crc.zip'));
+        const original = goodZip.getEntries()[0].header.crc;
+        assert.equal(original, 3528145192);
+        const newZipPath = destination + '/good_crc_new.zip';
+        goodZip.writeZip(newZipPath);
+        const newZip = new Zip(newZipPath);
+        const actual = newZip.getEntries()[0].header.crc;
+        assert.equal(actual, original);
+    });
+});