[Mac] Fix official build break where the builders do not have git installed.

This fixes the bug two ways to be extra defensive.

BUG=none
TEST=tweak_info_plist succeeds on internal waterfall

Review URL: http://codereview.chromium.org/7037030

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@85782 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 12 insertions, 2 deletions

diff --git a/chrome/tools/build/mac/tweak_info_plist b/chrome/tools/build/mac/tweak_info_plist
index eeec906..37a8bdd 100755
--- a/chrome/tools/build/mac/tweak_info_plist
+++ b/chrome/tools/build/mac/tweak_info_plist
@@ -41,8 +41,14 @@ def _GetOutput(args):
 
 
 def _GetOutputNoError(args):
-  """Behaves identically to _GetOutput() but ignores stderr."""
-  proc = subprocess.Popen(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+  """Similar to _GetOutput() but ignores stderr. If there's an error launching
+  the child (like file not found), the exception will be caught and (None, 1)
+  will be returned to mimic quiet failure."""
+  try:
+    proc = subprocess.Popen(args, stdout=subprocess.PIPE,
+                            stderr=subprocess.PIPE)
+  except OSError:
+    return (None, 1)
   (stdout, stderr) = proc.communicate()
   return (stdout, proc.returncode)
 
@@ -122,6 +128,10 @@ def _GetSCMInfo():
       # authentication scheme in use.
       scm_path = svn_url[len(svn_repo_root):]
 
+  # If the desired information was found via SVN, return it now.
+  if scm_revision != None and scm_path != None:
+    return (scm_path, scm_revision)
+
   # If a SVN revision number couldn't be found, try getting it through git.
   (stdout, retval) = _GetOutputNoError(['git', 'log', '-1',
                                         '--grep=git-svn-id', '--format=%b'])