Merge lp:~schwab-linux-m68k/bzr-fastimport/parentless into lp:bzr-fastimport

[Andreas Schwab]

The proper way to create a parentless commit is to emit a reset command for the branch
without a following from command. That obviates the need to invent a possibly conflicting
branch name.

Unmerged revisions

357. By Andreas Schwab on 2012-05-08

Properly create parentless commit

=== modified file 'exporter.py'
--- exporter.py	2012-02-28 16:16:13 +0000
+++ exporter.py	2012-05-08 09:49:19 +0000
@@ -187,14 +187,11 @@
 
         # Load the marks and initialise things accordingly
         self.revid_to_mark = {}
-        self.branch_names = {}
         if self.import_marks_file:
             marks_info = marks_file.import_marks(self.import_marks_file)
             if marks_info is not None:
                 self.revid_to_mark = dict((r, m) for m, r in
                     marks_info.items())
-                # These are no longer included in the marks file
-                #self.branch_names = marks_info[1]
 
     def interesting_history(self):
         if self.revision:
@@ -339,12 +336,7 @@
         ncommits = len(self.revid_to_mark)
         nparents = len(revobj.parent_ids)
         if nparents == 0:
-            if ncommits:
-                # This is a parentless commit but it's not the first one
-                # output. We need to create a new temporary branch for it
-                # otherwise git-fast-import will assume the previous commit
-                # was this one's parent
-                ref = self._next_tmp_ref()
+            self.print_cmd(commands.ResetCommand(ref, None))
             parent = bzrlib.revision.NULL_REVISION
         else:
             parent = revobj.parent_ids[0]
@@ -617,13 +609,3 @@
                                      'valid in git.', git_ref)
                         continue
                 self.print_cmd(commands.ResetCommand(git_ref, ":" + str(mark)))
-
-    def _next_tmp_ref(self):
-        """Return a unique branch name. The name will start with "tmp"."""
-        prefix = 'tmp'
-        if prefix not in self.branch_names:
-            self.branch_names[prefix] = 0
-        else:
-            self.branch_names[prefix] += 1
-            prefix = '%s.%d' % (prefix, self.branch_names[prefix])
-        return 'refs/heads/%s' % prefix