depot_tools: Add git svn find-rev for safesync_url parsing (commonly LKGR link).

scm.py

Index: scm.py
===================================================================
--- scm.py	(revision 108803)
+++ scm.py	(working copy)
@@ -379,6 +379,37 @@
     root = GIT.Capture(['rev-parse', '--show-cdup'], cwd=cwd).strip()
     return os.path.abspath(os.path.join(cwd, root))
 
+  @staticmethod
+  def GetGitSvnHeadRev(cwd):
+    """Get the most recently pulled git-svn revision."""

[M-A Ruel, 2011/11/08 14:29:20]

"Gets", you see the deal. :)

[Dan Beam, 2011/11/09 10:31:15]

Done.

+    try:
+      output = GIT.Capture(['svn', 'info'], cwd=cwd)
+      match = re.search('\nRevision: ([0-9]+)\n', output)

[M-A Ruel, 2011/11/08 14:29:20]

you should use ^$ instead of \n ? e.g. :
re.search(r'^bar$', 'foo\nbar\nbaz\n', re.MULTILINE)

[Dan Beam, 2011/11/09 10:31:15]

Done. (tried this a couple times before and it just wasn't working...)

+      return int(match.group(1)) if match else None
+    except (subprocess2.CalledProcessError, ValueError):
+      return None
+
+  @staticmethod
+  def GetSha1ForSvnRev(cwd, rev):
+    """Returns a corresponding git sha1 for a SVN revision."""
+    if not GIT.IsGitSvn(cwd=cwd):
+      return None
+    try:
+      lines = GIT.Capture(
+          ['svn', 'find-rev', 'r' + rev], cwd=cwd).splitlines(True)

[M-A Ruel, 2011/11/08 14:29:20]

Why True?

What if isinstance(rev, int) ?

[Dan Beam, 2011/11/09 10:31:15]

Oh, guess I didn't need that, you're right.  Thought it preserved \n+, but it
just leaves a \n on the end of lines.  D'oh.
Done. (just homogenized to string)

+      return lines[-1].strip() if len(lines) else None
+    except subprocess2.CalledProcessError:
+      return None
+
+  @staticmethod
+  def VerifyRevisionFormat(cwd, rev):

[M-A Ruel, 2011/11/08 14:29:20]

I'd rename the function, you are not verifying the 'format' but the 'validity'.

IsRevisionValid is clearer to me about what the function does.

[Dan Beam, 2011/11/09 10:31:15]

Done.

+    """Verifies the revision is a proper git revision."""
+    try:
+      GIT.Capture(['rev-parse', rev], cwd=cwd)
+      return True
+    except subprocess2.CalledProcessError:
+      return False
+
   @classmethod
   def AssertVersion(cls, min_version):
     """Asserts git's version is at least min_version."""
@@ -929,6 +960,18 @@
       directory = parent
     return GetCasedPath(directory)
 
+  @staticmethod
+  def VerifyRevisionFormat(cwd, rev, url=None):
+    """Verifies the revision looks like an SVN revision"""
+    try:
+      if url:
+        SVN.Capture(['info', '-r', rev, url])

[M-A Ruel, 2011/11/08 14:29:20]

If it is an url, it should simply use the format url@revision so this function
shouldn't special case. Fix the caller instead.

[Dan Beam, 2011/11/09 10:31:15]

Done.

+      else:
+        SVN.Capture(['info', '-r', rev])
+      return True
+    except subprocess2.CalledProcessError:
+      return False
+
   @classmethod
   def AssertVersion(cls, min_version):
     """Asserts svn's version is at least min_version."""