Revert of If the destination directory doesn't contain the desired repo, delete it

gclient_scm.py

Index: gclient_scm.py
diff --git a/gclient_scm.py b/gclient_scm.py
index 0392c4e6d57b842af88f48972e94d8e6d4e64430..c80575e0d2fae66f8a5a134443e3bd1db3d643b2 100644
--- a/gclient_scm.py
+++ b/gclient_scm.py
@@ -221,13 +221,6 @@
 
   def GetCheckoutRoot(self):
     return scm.GIT.GetCheckoutRoot(self.checkout_path)
-
-  def GetRemoteURL(self, options, cwd=None):
-    try:
-      return self._Capture(['config', 'remote.%s.url' % self.remote],
-                           cwd=cwd or self.checkout_path).rstrip()
-    except (OSError, subprocess2.CalledProcessError):
-      return None
 
   def GetRevisionDate(self, _revision):
     """Returns the given revision's date in ISO-8601 format (which contains the
@@ -286,6 +279,22 @@
 
     gclient_utils.CheckCallAndFilter(cmd4, **kwargs)
 
+  def _FetchAndReset(self, revision, file_list, options):
+    """Equivalent to git fetch; git reset."""
+    quiet = []
+    if not options.verbose:
+      quiet = ['--quiet']
+    self._UpdateBranchHeads(options, fetch=False)
+
+    fetch_cmd = [
+      '-c', 'core.deltaBaseCacheLimit=2g', 'fetch', self.remote, '--prune']
+    self._Run(fetch_cmd + quiet, options, retry=True)
+    self._Run(['reset', '--hard', revision] + quiet, options)
+    self.UpdateSubmoduleConfig()
+    if file_list is not None:
+      files = self._Capture(['ls-files']).splitlines()
+      file_list.extend([os.path.join(self.checkout_path, f) for f in files])
+
   def update(self, options, args, file_list):
     """Runs git to update or transparently checkout the working copy.
 
@@ -372,9 +381,34 @@
                                 '\tAnd run gclient sync again\n'
                                 % (self.relpath, rev_str, self.relpath))
 
+    # See if the url has changed (the unittests use git://foo for the url, let
+    # that through).
+    current_url = self._Capture(['config', 'remote.%s.url' % self.remote])
+    return_early = False
+    # TODO(maruel): Delete url != 'git://foo' since it's just to make the
+    # unit test pass. (and update the comment above)
+    # Skip url auto-correction if remote.origin.gclient-auto-fix-url is set.
+    # This allows devs to use experimental repos which have a different url
+    # but whose branch(s) are the same as official repos.
+    if (current_url != url and
+        url != 'git://foo' and
+        subprocess2.capture(
+            ['git', 'config', 'remote.%s.gclient-auto-fix-url' % self.remote],
+            cwd=self.checkout_path).strip() != 'False'):
+      print('_____ switching %s to a new upstream' % self.relpath)
+      # Make sure it's clean
+      self._CheckClean(rev_str)
+      # Switch over to the new upstream
+      self._Run(['remote', 'set-url', self.remote, url], options)
+      self._FetchAndReset(revision, file_list, options)
+      return_early = True
+
     # Need to do this in the normal path as well as in the post-remote-switch
     # path.
     self._PossiblySwitchCache(url, options)
+
+    if return_early:
+      return self._Capture(['rev-parse', '--verify', 'HEAD'])
 
     cur_branch = self._GetCurrentBranch()
 
@@ -781,7 +815,8 @@
         # to relax this restriction in the future to allow for smarter cache
         # repo update schemes (such as pulling the same repo, but from a
         # different host).
-        existing_url = self.GetRemoteURL(options, cwd=folder)
+        existing_url = self._Capture(['config', 'remote.%s.url' % self.remote],
+                                     cwd=folder)
         assert self._NormalizeGitURL(existing_url) == self._NormalizeGitURL(url)
 
         if use_reference:
@@ -1050,13 +1085,6 @@
   def GetCheckoutRoot(self):
     return scm.SVN.GetCheckoutRoot(self.checkout_path)
 
-  def GetRemoteURL(self, options):
-    try:
-      local_info = scm.SVN.CaptureLocalInfo([os.curdir], self.checkout_path)
-    except (OSError, subprocess2.CalledProcessError):
-      return None
-    return local_info.get('URL')
-
   def GetRevisionDate(self, revision):
     """Returns the given revision's date in ISO-8601 format (which contains the
     time zone)."""
@@ -1096,12 +1124,25 @@
     Raises:
       Error: if can't get URL for relative path.
     """
+    # Only update if git or hg is not controlling the directory.
+    git_path = os.path.join(self.checkout_path, '.git')
+    if os.path.exists(git_path):
+      print('________ found .git directory; skipping %s' % self.relpath)
+      return
+
+    hg_path = os.path.join(self.checkout_path, '.hg')
+    if os.path.exists(hg_path):
+      print('________ found .hg directory; skipping %s' % self.relpath)
+      return
+
     if args:
       raise gclient_utils.Error("Unsupported argument(s): %s" % ",".join(args))
 
     # revision is the revision to match. It is None if no revision is specified,
     # i.e. the 'deps ain't pinned'.
     url, revision = gclient_utils.SplitUrlRevision(self.url)
+    # Keep the original unpinned url for reference in case the repo is switched.
+    base_url = url
     managed = True
     if options.revision:
       # Override the revision number.
@@ -1247,6 +1288,53 @@
       from_info_live = scm.SVN.CaptureRemoteInfo(from_info['URL'])
       revision = str(from_info_live['Revision'])
       rev_str = ' at %s' % revision
+
+    if from_info['URL'] != base_url:
+      # The repository url changed, need to switch.
+      try:
+        to_info = scm.SVN.CaptureRemoteInfo(url)
+      except (gclient_utils.Error, subprocess2.CalledProcessError):
+        # The url is invalid or the server is not accessible, it's safer to bail
+        # out right now.
+        raise gclient_utils.Error('This url is unreachable: %s' % url)
+      can_switch = ((from_info['Repository Root'] != to_info['Repository Root'])
+                    and (from_info['UUID'] == to_info['UUID']))
+      if can_switch:
+        print('\n_____ relocating %s to a new checkout' % self.relpath)
+        # We have different roots, so check if we can switch --relocate.
+        # Subversion only permits this if the repository UUIDs match.
+        # Perform the switch --relocate, then rewrite the from_url
+        # to reflect where we "are now."  (This is the same way that
+        # Subversion itself handles the metadata when switch --relocate
+        # is used.)  This makes the checks below for whether we
+        # can update to a revision or have to switch to a different
+        # branch work as expected.
+        # TODO(maruel):  TEST ME !
+        command = ['switch', '--relocate',
+                   from_info['Repository Root'],
+                   to_info['Repository Root'],
+                   self.relpath]
+        self._Run(command, options, cwd=self._root_dir)
+        from_info['URL'] = from_info['URL'].replace(
+            from_info['Repository Root'],
+            to_info['Repository Root'])
+      else:
+        if not options.force and not options.reset:
+          # Look for local modifications but ignore unversioned files.
+          for status in scm.SVN.CaptureStatus(None, self.checkout_path):
+            if status[0][0] != '?':
+              raise gclient_utils.Error(
+                  ('Can\'t switch the checkout to %s; UUID don\'t match and '
+                   'there is local changes in %s. Delete the directory and '
+                   'try again.') % (url, self.checkout_path))
+        # Ok delete it.
+        print('\n_____ switching %s to a new checkout' % self.relpath)
+        gclient_utils.rmtree(self.checkout_path)
+        # We need to checkout.
+        command = ['checkout', url, self.checkout_path]
+        command = self._AddAdditionalUpdateFlags(command, options, revision)
+        self._RunAndGetFileList(command, options, file_list, self._root_dir)
+        return self.Svnversion()
 
     # If the provided url has a revision number that matches the revision
     # number of the existing directory, then we don't need to bother updating.
@@ -1314,6 +1402,12 @@
       return self.update(options, [], file_list)
 
     if not os.path.isdir(os.path.join(self.checkout_path, '.svn')):
+      if os.path.isdir(os.path.join(self.checkout_path, '.git')):
+        print('________ found .git directory; skipping %s' % self.relpath)
+        return
+      if os.path.isdir(os.path.join(self.checkout_path, '.hg')):
+        print('________ found .hg directory; skipping %s' % self.relpath)
+        return
       if not options.force:
         raise gclient_utils.Error('Invalid checkout path, aborting')
       print(