Merge pull request #10160 from liusy182/liusy182-10128-asar

Return empty string when fs.readFile with 'utf8' option from asar file

lib/common/asar.js

@@ -457,26 +457,6 @@
       }
       if (typeof options === 'function') {
         callback = options
-        options = void 0
-      }
-      const archive = getOrCreateArchive(asarPath)
-      if (!archive) {
-        return invalidArchiveError(asarPath, callback)
-      }
-      const info = archive.getFileInfo(filePath)
-      if (!info) {
-        return notFoundError(asarPath, filePath, callback)
-      }
-      if (info.size === 0) {
-        return process.nextTick(function () {
-          callback(null, new Buffer(0))
-        })
-      }
-      if (info.unpacked) {
-        const realPath = archive.copyFileOut(filePath)
-        return fs.readFile(realPath, options, callback)
-      }
-      if (!options) {
         options = {
           encoding: null
         }
@@ -488,6 +468,25 @@
         throw new TypeError('Bad arguments')
       }
       const {encoding} = options
+
+      const archive = getOrCreateArchive(asarPath)
+      if (!archive) {
+        return invalidArchiveError(asarPath, callback)
+      }
+      const info = archive.getFileInfo(filePath)
+      if (!info) {
+        return notFoundError(asarPath, filePath, callback)
+      }
+      if (info.size === 0) {
+        return process.nextTick(function () {
+          callback(null, encoding ? '' : new Buffer(0))
+        })
+      }
+      if (info.unpacked) {
+        const realPath = archive.copyFileOut(filePath)
+        return fs.readFile(realPath, options, callback)
+      }
+
       const buffer = new Buffer(info.size)
       const fd = archive.getFd()
       if (!(fd >= 0)) {

spec/asar-spec.js

@@ -99,6 +99,15 @@ describe('asar package', function () {
         })
       })
 
+      it('reads from a empty file with encoding', function (done) {
+        var p = path.join(fixtures, 'asar', 'empty.asar', 'file1')
+        fs.readFile(p, 'utf8', function (err, content) {
+          assert.equal(err, null)
+          assert.equal(content, '')
+          done()
+        })
+      })
+
       it('reads a linked file', function (done) {
         var p = path.join(fixtures, 'asar', 'a.asar', 'link1')
         fs.readFile(p, function (err, content) {