gclient: Add a minimum git version check.

gclient_scm.py

Index: gclient_scm.py
diff --git a/gclient_scm.py b/gclient_scm.py
index 034dc2df6c8bdef41dc7f8460bc8ca356036756a..aa5a05d33b6c60692382915553df50f92ab7e885 100644
--- a/gclient_scm.py
+++ b/gclient_scm.py
@@ -115,6 +115,8 @@ class GitWrapper(SCMWrapper, scm.GIT):
     if args:
       raise gclient_utils.Error("Unsupported argument(s): %s" % ",".join(args))
 
+    self._CheckMinVersion("1.6.1")
+
     url, revision = gclient_utils.SplitUrlRevision(self.url)
     rev_str = ""
     if options.revision:
@@ -185,6 +187,18 @@ class GitWrapper(SCMWrapper, scm.GIT):
       files = self._Run(['diff', '--name-only', merge_base]).split()
       file_list.extend([os.path.join(self.checkout_path, f) for f in files])
 
+  def _CheckMinVersion(self, min_version):
+    version = self._Run(['--version']).split()[-1]
+    version_list = map(int, version.split('.'))
+    min_version_list = map(int, min_version.split('.'))

[M-A Ruel, 2009/12/11 19:51:54]

Nice idea, I wouldn't have thought about that.

+    for min_ver in min_version_list:
+      ver = version_list.pop(0)
+      if min_ver > ver:
+        raise gclient_utils.Error('git version %s < minimum required %s' %
+                                  (version, min_version))
+      elif min_ver < ver:
+        return
+
   def _Run(self, args, cwd=None, checkrc=True, redirect_stdout=True):
     # TODO(maruel): Merge with Capture?
     if cwd is None: