From a4c07ec7ae8a384e9514370c37e533028bc7f2dc Mon Sep 17 00:00:00 2001
From: Pierre-Yves Chibon <pingou@pingoured.fr>
Date: Jul 21 2015 10:09:36 +0000
Subject: Add a method to pull changes from a remote repo into the local one


---

diff --git a/pagure/lib/repo.py b/pagure/lib/repo.py
index 12dbd66..105b5b9 100644
--- a/pagure/lib/repo.py
+++ b/pagure/lib/repo.py
@@ -11,6 +11,8 @@
 
 import pygit2
 
+import pagure.exceptions
+
 
 class PagureRepo(pygit2.Repository):
     """ An utility class allowing to go around pygit2's inability to be
@@ -25,3 +27,34 @@ class PagureRepo(pygit2.Repository):
             remote.push([refname])
         else:
             remote.push(refname)
+
+    def pull(self, remote_name='origin', branch='master'):
+        ''' pull changes for the specified remote (defaults to origin).
+
+        Code from MichaelBoselowitz at:
+        https://github.com/MichaelBoselowitz/pygit2-examples/blob/
+            68e889e50a592d30ab4105a2e7b9f28fac7324c8/examples.py#L58
+        licensed under the MIT license.
+        '''
+
+        for remote in self.remotes:
+            if remote.name == remote_name:
+                remote.fetch()
+                remote_master_id = self.lookup_reference(
+                    'refs/remotes/origin/%s' % branch).target
+                merge_result, _ = self.merge_analysis(remote_master_id)
+                # Up to date, do nothing
+                if merge_result & pygit2.GIT_MERGE_ANALYSIS_UP_TO_DATE:
+                    return
+                # We can just fastforward
+                elif merge_result & pygit2.GIT_MERGE_ANALYSIS_FASTFORWARD:
+                    self.checkout_tree(self.get(remote_master_id))
+                    master_ref = self.lookup_reference(
+                        'refs/heads/%s' % branch)
+                    master_ref.set_target(remote_master_id)
+                    self.head.set_target(remote_master_id)
+                elif merge_result & pygit2.GIT_MERGE_ANALYSIS_NORMAL:
+                    raise pagure.exceptions.PagureException(
+                        'Pulling remote changes leads to a conflict')
+                else:
+                    raise AssertionError('Unknown merge analysis result')