msvs: fix regression in r1378, environment not set up properly for multiple actions on one input

pylib/gyp/generator/msvs.py

 # Copyright (c) 2012 Google Inc. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import copy
 import ntpath
 import os
 import posixpath
 import re
 import subprocess
@@ skipping 1439 matching lines @@
   fh = open(filename, 'w')
   fh.write(data)
   fh.close()
 
 
 def _AddActions(actions_to_add, spec, relative_path_of_gyp_file, vcproj_file):
   # Add actions.
   actions = spec.get('actions', [])
   # Don't setup_env every time. When all the actions are run together in one
   # batch file in VS, the PATH will grow too long.
-  first_action = True
+  have_setup_env = {}

[jeanluc1, 2012/05/16 22:11:06]

Please document what this variable does (e.g. key/value)

   for a in actions:
-    cmd = _BuildCommandLineForRule(spec, a, has_input_path=False,
-                                   do_setup_env=first_action)
     # Attach actions to the gyp file if nothing else is there.
     inputs = a.get('inputs') or [relative_path_of_gyp_file]
+    attached_to = inputs[0]
+    need_setup_env = attached_to not in have_setup_env
+    cmd = _BuildCommandLineForRule(spec, a, has_input_path=False,
+                                   do_setup_env=need_setup_env)
+    have_setup_env[attached_to] = True
     if vcproj_file:
       # Additionally, on MSVS 2008, we record the command in a file
       # and add this as a dependency so that when the command changes,
       # the action gets re-run.  This is not necessary on MSVS 2010
       # which tracks command changes for us.
       command_file = '%s_%s.gypcmd' % (vcproj_file, a['action_name'])
       _WriteFileIfChanged(command_file, cmd)
       inputs = inputs + [os.path.basename(command_file)]
     # Add the action.
     _AddActionStep(actions_to_add,
                    inputs=inputs,
                    outputs=a.get('outputs', []),
                    description=a.get('message', a['action_name']),
                    command=cmd)
-    first_action = False
 
 
 def _WriteMSVSUserFile(project_path, version, spec):
   # Add run_as and test targets.
   if 'run_as' in spec:
     run_as = spec['run_as']
     action = run_as.get('action', [])
     environment = run_as.get('environment', [])
     working_directory = run_as.get('working_directory', '.')
   elif int(spec.get('test', 0)):
@@ skipping 1626 matching lines @@
   action_spec.extend(
       # TODO(jeanluc) 'Document' for all or just if as_sources?
       [['FileType', 'Document'],
        ['Command', command],
        ['Message', description],
        ['Outputs', outputs]
       ])
   if additional_inputs:
     action_spec.append(['AdditionalInputs', additional_inputs])
   actions_spec.append(action_spec)