Fix win/cross of the credential provider.

Bug: 907469
Change-Id: I11eef2154474685461408d7932a4406001ee0174
Reviewed-on: https://chromium-review.googlesource.com/c/1359066
Commit-Queue: Roger Tawa <rogerta@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#613238}

chrome/credential_provider/build/make_setup.py

@@ -44,10 +44,24 @@ All paths can be absolute or relative to $root_build_dir.
 
 import argparse
 import os
+import shutil
 import subprocess
 import sys
 
 
+def GetLZMAExec(src_path):
+  """Gets the path to the 7zip compression command line tool.
+
+  Args:
+    src_path: Full path to the source root
+
+  Returns:
+    The executable command to run the 7zip compressor.
+  """
+  return (os.path.join(src_path, r'third_party\lzma_sdk\7zr.exe')
+          if sys.platform == 'win32' else '7zr')
+
+
 def main():
   parser = argparse.ArgumentParser(
       description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter)
@@ -74,7 +88,7 @@ def main():
   gcp_installer_fn = os.path.join(args.root_build_path, 'gcp_installer.exe')
   gcp_7z_fn = os.path.join(args.root_build_path, 'gcp.7z')
 
-  sz_fn = os.path.join(args.src_path, r'third_party\lzma_sdk\7zr.exe')
+  sz_fn = GetLZMAExec(args.src_path)
   sfx_fn = os.path.join(args.root_build_path, 'gcp_sfx.exe')
 
   # Build the command line for updating files in the GCP 7z archive.
@@ -110,7 +124,7 @@ def main():
 
   # 7zip and copy commands don't have a "silent" mode, so redirecting stdout
   # and stderr to nul.
-  with open('nul') as nul_file:
+  with open(os.devnull) as nul_file:
     os.chdir(args.root_build_path)
     subprocess.check_call(cmd + ['gaia1_0.dll'], stdout=nul_file)
     subprocess.check_call(cmd + ['gcp_setup.exe'], stdout=nul_file)
@@ -118,8 +132,11 @@ def main():
 
   # Combine the SFX module with the archive to make a self extracting
   # executable.
-  command = 'copy /b %s + %s %s > nul' % (sfx_fn, gcp_7z_fn, gcp_installer_fn)
-  subprocess.check_call(command, shell=True)
+  with open(gcp_installer_fn, 'wb') as output:
+    with open (sfx_fn, 'rb') as input:
+      shutil.copyfileobj(input, output)
+    with open (gcp_7z_fn, 'rb') as input:
+      shutil.copyfileobj(input, output)
 
   return 0