Writes predecessor headers in the commits

ecbaldwin · ecbaldwin · commit 42ec41d74e07 · 2018-01-08T21:59:04.000-07:00
diff --git a/git/objects/commit.py b/git/objects/commit.py
@@ -66,12 +66,12 @@ class Commit(base.Object, Iterable, Diffable, Traversable, Serializable):
     __slots__ = ("tree",
                  "author", "authored_date", "author_tz_offset",
                  "committer", "committed_date", "committer_tz_offset",
-                 "message", "parents", "encoding", "gpgsig")
+                 "message", "parents", "encoding", "gpgsig", "predecessors")
     _id_attribute_ = "hexsha"
 
     def __init__(self, repo, binsha, tree=None, author=None, authored_date=None, author_tz_offset=None,
                  committer=None, committed_date=None, committer_tz_offset=None,
-                 message=None, parents=None, encoding=None, gpgsig=None):
+                 message=None, parents=None, encoding=None, gpgsig=None, predecessors=None):
         """Instantiate a new Commit. All keyword arguments taking None as default will
         be implicitly set on first query.
 
@@ -101,6 +101,9 @@ def __init__(self, repo, binsha, tree=None, author=None, authored_date=None, aut
         :param parents:
             List or tuple of Commit objects which are our parent(s) in the commit
             dependency graph
+        :param predecessors:
+            List or tuple of Commit objects which this commit replaces after rebasing or amending
+            rewrite graph
         :return: git.Commit
 
         :note:
@@ -132,6 +135,8 @@ def __init__(self, repo, binsha, tree=None, author=None, authored_date=None, aut
             self.encoding = encoding
         if gpgsig is not None:
             self.gpgsig = gpgsig
+        if predecessors is not None:
+            self.predecessors = predecessors
 
     @classmethod
     def _get_intermediate_items(cls, commit):
@@ -280,7 +285,7 @@ def _iter_from_process_or_stream(cls, repo, proc_or_stream):
 
     @classmethod
     def create_from_tree(cls, repo, tree, message, parent_commits=None, head=False, author=None, committer=None,
-                         author_date=None, commit_date=None):
+                         author_date=None, commit_date=None, predecessors=None):
         """Commit the given tree, creating a commit object.
 
         :param repo: Repo object the commit should be part of
@@ -325,6 +330,15 @@ def create_from_tree(cls, repo, tree, message, parent_commits=None, head=False,
             # end check parent commit types
         # END if parent commits are unset
 
+        if predecessors is None:
+            predecessors=list()
+        else:
+            for p in predecessors:
+                if not isinstance(p, cls):
+                    raise ValueError("Replaced commit '%r' must be of type %s" % (p, cls))
+            # end check predecessors commit types
+        # END if predecessors commits are unset
+
         # retrieve all additional information, create a commit object, and
         # serialize it
         # Generally:
@@ -375,7 +389,7 @@ def create_from_tree(cls, repo, tree, message, parent_commits=None, head=False,
         new_commit = cls(repo, cls.NULL_BIN_SHA, tree,
                          author, author_time, author_offset,
                          committer, committer_time, committer_offset,
-                         message, parent_commits, conf_encoding)
+                         message, parent_commits, conf_encoding, predecessors=predecessors)
 
         stream = BytesIO()
         new_commit._serialize(stream)
@@ -434,6 +448,9 @@ def _serialize(self, stream):
         except AttributeError:
             pass
 
+        for p in self.predecessors:
+            write(("predecessor %s\n" % p).encode('ascii'))
+
         write(b"\n")
 
         # write plain bytes, be sure its encoded according to our encoding
