Fix commit message editing in >= 2.11

Detect the gerrit version on startup and on any reconnection.
When submitting commit message edits, use the change edit API
in 2.11 or greater as the old API has been removed.

Change-Id: Idcba9fc6d424311658b0470410c820015bac9590

gertty/sync.py

@@ -186,6 +186,19 @@ class SyncOwnAccountTask(Task):
                                    remote.get('username'),
                                    remote.get('email'))
 
+class GetVersionTask(Task):
+    def __repr__(self):
+        return '<GetVersionTask>'
+
+    def __eq__(self, other):
+        if other.__class__ == self.__class__:
+            return True
+        return False
+
+    def run(self, sync):
+        version = sync.get('config/server/version')
+        sync.setRemoteVersion(version)
+
 class SyncProjectListTask(Task):
     def __repr__(self):
         return '<SyncProjectListTask>'
@@ -1080,9 +1093,17 @@ class ChangeCommitMessageTask(Task):
             revision.pending_message = False
             data = dict(message=revision.message)
             # Inside db session for rollback
-            sync.post('changes/%s/revisions/%s/message' %
-                      (revision.change.id, revision.commit),
-                      data)
+            if sync.version < (2,11,0):
+                sync.post('changes/%s/revisions/%s/message' %
+                          (revision.change.id, revision.commit),
+                          data)
+            else:
+                edit = sync.get('changes/%s/edit' % revision.change.id)
+                if edit is not None:
+                    raise Exception("Edit already in progress on change %s" %
+                                    (revision.change.number,))
+                sync.put('changes/%s/edit:message' % (revision.change.id,), data)
+                sync.post('changes/%s/edit:publish' % (revision.change.id,), {})
             change_id = revision.change.id
         sync.submitTask(SyncChangeTask(change_id, priority=self.priority))
 
@@ -1251,6 +1272,7 @@ class Sync(object):
     def __init__(self, app):
         self.user_agent = 'Gertty/%s %s' % (gertty.version.version_info.release_string(),
                                             requests.utils.default_user_agent())
+        self.version = (0, 0, 0)
         self.offline = False
         self.account_id = None
         self.app = app
@@ -1264,6 +1286,7 @@ class Sync(object):
             authclass = requests.auth.HTTPDigestAuth
         self.auth = authclass(
             self.app.config.username, self.app.config.password)
+        self.submitTask(GetVersionTask(HIGH_PRIORITY))
         self.submitTask(SyncOwnAccountTask(HIGH_PRIORITY))
         self.submitTask(CheckReposTask(HIGH_PRIORITY))
         self.submitTask(UploadReviewsTask(HIGH_PRIORITY))
@@ -1310,6 +1333,7 @@ class Sync(object):
         except requests.ConnectionError, e:
             self.log.warning("Offline due to: %s" % (e,))
             if not self.offline:
+                self.submitTask(GetVersionTask(HIGH_PRIORITY))
                 self.submitTask(UploadReviewsTask(HIGH_PRIORITY))
             self.offline = True
             self.app.status.update(offline=True, refresh=False)
@@ -1415,3 +1439,16 @@ class Sync(object):
                 return
         task = SyncChangesByCommitsTask([commit], priority)
         self.submitTask(task)
+
+    def setRemoteVersion(self, version):
+        base = version.split('-')[0]
+        parts = base.split('.')
+        major = minor = micro = 0
+        if len(parts) > 0:
+            major = int(parts[0])
+        if len(parts) > 1:
+            minor = int(parts[1])
+        if len(parts) > 2:
+            micro = int(parts[2])
+        self.version = (major, minor, micro)
+        self.log.info("Remote version is: %s (parsed as %s)" % (version, self.version))