gclient: implement a less hacky relative URL implementation

gclient_utils.py

 # Copyright 2009 Google Inc.  All Rights Reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
 #      http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 20 matching lines @@
     # Make sure ssh://test@example.com/test.git@stable works
     regex = r"(ssh://(?:[\w]+@)?[-\w:\.]+/[-\w\./]+)(?:@(.+))?"
     components = re.search(regex, url).groups()
   else:
     components = url.split("@")
     if len(components) == 1:
       components += [None]
   return tuple(components)
 
 
+def FullUrlFromRelative(base_url, url):
+  # Find the forth '/' and strip from there. A bit hackish.
+  return '/'.join(base_url.split('/')[:4]) + url
+
+
+def FullUrlFromRelative2(base_url, url):

[M-A Ruel, 2009/12/15 18:49:42]

Frankly, I would have prefered it to be SCM-dependent. The main issue is that
git cannot have sub-directory checkout so using this is *always* appropriate
while the reverse is not true for FullUrlFromRelative(). Hence I think this
should be moved back to gclient_scm.py

[Mandeep Singh Baines, 2009/12/15 20:54:30]

k, I'll send out a CL to do that. I don't want to revert this change as it will
break the ChromiumOS build.

+  # Strip from last '/'
+  # Equivalent to unix basename
+  return base_url[:base_url.rfind('/')] + url
+
+
 def ParseXML(output):
   try:
     return xml.dom.minidom.parseString(output)
   except xml.parsers.expat.ExpatError:
     return None
 
 
 def GetNamedNodeText(node, node_name):
   child_nodes = node.getElementsByTagName(node_name)
   if not child_nodes:
@@ skipping 207 matching lines @@
     raise Error(msg)
 
 
 def IsUsingGit(root, paths):
   """Returns True if we're using git to manage any of our checkouts.
   |entries| is a list of paths to check."""
   for path in paths:
     if os.path.exists(os.path.join(root, path, '.git')):
       return True
   return False