fixup! Support specifying a pin for merges

Author: Tom Blauwendraat

git_aggregator/repo.py

@@ -45,7 +45,7 @@ def __init__(self, cwd, remotes, merges, target,
         :param remotes: list of remote linked to the repository. A remote is
         a dict {'name': '', 'url': ''}
         :param: merges list of merge to apply to build the aggregated
-        repository. A merge is a dict {'remote': '', 'ref': ''}
+        repository. A merge is a dict {'remote': '', 'ref': '', 'pin': ''}
         :param target:
         :param shell_command_after: an optional list of shell command to
         execute after the aggregation
@@ -242,17 +242,15 @@ def fetch(self):
         basecmd = ("git", "fetch")
         logger.info("Fetching required remotes")
         for merge in self.merges:
-            pin = remote.get("pin")
             cmd = basecmd + self._fetch_options(merge) + (merge["remote"],)
             if merge["remote"] not in self.fetch_all:
-                if pin:
+                if merge.get("pin"):
                     # Probably solvable, but a little too tricky for me to
                     # figure out right now
                     raise GitAggregatorException(
                         "Cannot use fetch_all with pin"
                     )
                 cmd += (merge["ref"],)
-            merge["pin"] = pin
             self.log_call(cmd, cwd=self.cwd)
 
     def rev_parse(self, ref):
@@ -311,8 +309,6 @@ def _switch_to_branch(self, branch_name):
         # check if the branch already exists
         logger.info("Switch to branch %s", branch_name)
         cmd = ['git', 'checkout', '-B', branch_name]
-        if ref is not None:
-            cmd.append(self.rev_parse(ref))
         self.log_call(cmd, cwd=self.cwd)
 
     def _execute_shell_command_after(self):
@@ -322,7 +318,12 @@ def _execute_shell_command_after(self):
 
     def _merge(self, merge):
         pin = merge.get("pin")
-        logger.info("Pull %s, %s, %s", merge["remote"], merge["ref"], pin or "no pin")
+        logger.info(
+            "Pull %s, %s, %s",
+            merge["remote"],
+            merge["ref"],
+            pin or "no pin"
+        )
         cmd = ("git", "pull", "--ff", "--no-rebase")
         if self.git_version >= (1, 7, 10):
             # --edit and --no-edit appear with Git 1.7.10