Issue 3498 - Improve file mapping / skipping logic

packagerGecko.py

 # coding: utf-8
 
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 import os
 import sys
 import re
 import hashlib
@@ skipping 320 matching lines @@
   params = {
     'baseDir': baseDir,
     'locales': locales,
     'releaseBuild': releaseBuild,
     'version': version.encode('utf-8'),
     'metadata': metadata,
     'contributors': contributors,
     'multicompartment': multicompartment,
   }
 
+  mapped = metadata.items('mapping') if metadata.has_section('mapping') else []
+  skip = [opt for opt, _ in mapped].append('chrome')
   files = Files(getPackageFiles(params), getIgnoredFiles(params),
                 process=lambda path, data: processFile(path, data, params))
   files['install.rdf'] = createManifest(params)
-  if metadata.has_section('mapping'):
-    files.readMappedFiles(metadata.items('mapping'))
-  files.read(baseDir, skip=('chrome'))
+  files.readMappedFiles(mapped)
+  files.read(baseDir, skip=skip)
   for name, path in getChromeSubdirs(baseDir, params['locales']).iteritems():
     if os.path.isdir(path):
-      files.read(path, 'chrome/%s' % name)
+      files.read(path, 'chrome/%s' % name, skip=skip)
   importLocales(params, files)
   fixupLocales(params, files)
   if not 'bootstrap.js' in files:
     addMissingFiles(params, files)
   if metadata.has_section('preprocess'):
     files.preprocess([f for f, _ in metadata.items('preprocess')])
   if keyFile:
     signFiles(files, keyFile)
   files.zip(outFile, sortKey=lambda x: '!' if x == 'META-INF/zigbert.rsa' else x)
 
 def autoInstall(baseDir, type, host, port, multicompartment=False):
   fileBuffer = StringIO()
   createBuild(baseDir, type=type, outFile=fileBuffer, multicompartment=multicompartment)
   urllib.urlopen('http://%s:%s/' % (host, port), data=fileBuffer.getvalue())