gclient: Add better error reporting and handling when there is a rebase conflict

When a rebase generates a conflict, report an error and exit immediately.
If in an existing conflict (no branch), report an error and exit immediately.

Review URL: http://codereview.chromium.org/496003

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@34459 0039d316-1c4b-4281-b951-d872f2087c98

gclient_scm.py

@@ -140,13 +140,32 @@ class GitWrapper(SCMWrapper, scm.GIT):
     new_base = 'origin'
     if revision:
       new_base = revision
-    cur_branch = self._Run(['symbolic-ref', 'HEAD']).split('/')[-1]
+    cur_branch = self._GetCurrentBranch()
+
+    # Check if we are in a rebase conflict
+    if cur_branch is None:
+      raise gclient_utils.Error('\n____ %s%s\n'
+                                '\tAlready in a conflict, i.e. (no branch).\n'
+                                '\tFix the conflict and run gclient again.\n'
+                                '\tOr to abort run:\n\t\tgit-rebase --abort\n'
+                                '\tSee man git-rebase for details.\n'
+                                 % (self.relpath, rev_str))
+
     merge_base = self._Run(['merge-base', 'HEAD', new_base])
     self._Run(['remote', 'update'], redirect_stdout=False)
     files = self._Run(['diff', new_base, '--name-only']).split()
     file_list.extend([os.path.join(self.checkout_path, f) for f in files])
     self._Run(['rebase', '-v', '--onto', new_base, merge_base, cur_branch],
-                redirect_stdout=False)
+                redirect_stdout=False, checkrc=False)
+
+    # If the rebase generated a conflict, abort and ask user to fix
+    if self._GetCurrentBranch() is None:
+      raise gclient_utils.Error('\n____ %s%s\n'
+                                '\nConflict while rebasing this branch.\n'
+                                'Fix the conflict and run gclient again.\n'
+                                'See man git-rebase for details.\n'
+                                % (self.relpath, rev_str))
+
     print "Checked out revision %s." % self.revinfo(options, (), None)
 
   def revert(self, options, args, file_list):
@@ -204,6 +223,15 @@ class GitWrapper(SCMWrapper, scm.GIT):
       elif min_ver < ver:
         return
 
+  def _GetCurrentBranch(self):
+    # Returns name of current branch
+    # Returns None if inside a (no branch)
+    tokens = self._Run(['branch']).split()
+    branch = tokens[tokens.index('*') + 1]
+    if branch == '(no':
+      return None
+    return branch
+
   def _Run(self, args, cwd=None, checkrc=True, redirect_stdout=True):
     # TODO(maruel): Merge with Capture?
     if cwd is None:

tests/gclient_scm_test.py

@@ -279,7 +279,7 @@ class SVNWrapperTestCase(BaseTestCase):
     scm.update(options, self.args, file_list)
 
 
-class GitWrapperTestCase(SuperMoxBaseTestBase):
+class GitWrapperTestCase(BaseTestCase):
   """This class doesn't use pymox."""
   class OptionsObject(object):
      def __init__(self, test_case, verbose=False, revision=None):
@@ -506,6 +506,29 @@ from :3
     self.assertEquals(scm.revinfo(options, (), None),
                       'a7142dc9f0009350b96a11f372b6ea658592aa95')
 
+  def testUpdateConflict(self):
+    if not self.enabled:
+      return
+    options = self.Options()
+    scm = gclient_scm.CreateSCM(url=self.url, root_dir=self.root_dir,
+                                relpath=self.relpath)
+    file_path = gclient_scm.os.path.join(self.base_path, 'b')
+    f = open(file_path, 'w').writelines('conflict\n')
+    scm._Run(['commit', '-am', 'test'])
+    exception = \
+        '\n____ .\n' \
+        '\nConflict while rebasing this branch.\n' \
+        'Fix the conflict and run gclient again.\n' \
+        'See man git-rebase for details.\n'
+    self.assertRaisesError(exception, scm.update, options, (), [])
+    exception = \
+        '\n____ .\n' \
+        '\tAlready in a conflict, i.e. (no branch).\n' \
+        '\tFix the conflict and run gclient again.\n' \
+        '\tOr to abort run:\n\t\tgit-rebase --abort\n' \
+        '\tSee man git-rebase for details.\n'
+    self.assertRaisesError(exception, scm.update, options, (), [])
+
   def testRevinfo(self):
     if not self.enabled:
       return