Fix GenerateDiff -- don't strip whitespace.

scm.py

 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """SCM-specific utility classes."""
 
 import cStringIO
 import glob
 import logging
 import os
@@ skipping 79 matching lines @@
   if val.isdigit():
     return int(val)
   else:
     return 0
 
 
 class GIT(object):
   current_version = None
 
   @staticmethod
-  def Capture(args, cwd, **kwargs):
+  def Capture(args, cwd, strip_out=True, **kwargs):
     env = os.environ.copy()
     # 'cat' is a magical git string that disables pagers on all platforms.
     env['GIT_PAGER'] = 'cat'
-    return subprocess2.check_output(
+    output = subprocess2.check_output(
         ['git'] + args,
-        cwd=cwd, stderr=subprocess2.PIPE, env=env, **kwargs).strip()
+        cwd=cwd, stderr=subprocess2.PIPE, env=env, **kwargs)
+    return output.strip() if strip_out else output
 
   @staticmethod
   def CaptureStatus(files, cwd, upstream_branch):
     """Returns git status.
 
     @files can be a string (one file) or a list of files.
 
     Returns an array of (status, file) tuples."""
     if upstream_branch is None:
       upstream_branch = GIT.GetUpstreamBranch(cwd)
@@ skipping 235 matching lines @@
     command = ['diff', '-p', '--no-color', '--no-prefix', '--no-ext-diff',
                branch + "..." + branch_head]
     if full_move:
       command.append('--no-renames')
     else:
       command.append('-C')
     # TODO(maruel): --binary support.
     if files:
       command.append('--')
       command.extend(files)
-    diff = GIT.Capture(command, cwd=cwd).splitlines(True)
+    diff = GIT.Capture(command, cwd=cwd, strip_out=False).splitlines(True)
     for i in range(len(diff)):
       # In the case of added files, replace /dev/null with the path to the
       # file being added.
       if diff[i].startswith('--- /dev/null'):
         diff[i] = '--- %s' % diff[i+1][4:]
     return ''.join(diff)
 
   @staticmethod
   def GetDifferentFiles(cwd, branch=None, branch_head='HEAD'):
     """Returns the list of modified files between two branches."""
@@ skipping 733 matching lines @@
         # revert, like for properties.
         if not os.path.isdir(cwd):
           # '.' was deleted. It's not worth continuing.
           return
         try:
           SVN.Capture(['revert', file_status[1]], cwd=cwd)
         except subprocess2.CalledProcessError:
           if not os.path.exists(file_path):
             continue
           raise