If a patch is not changed when pushing, reuse the same commit object

It should be marginally faster since we don't have to create a new
commit object, but mostly it's a cleanliness issue: rewriting history
when we don't have to is bad.

Signed-off-by: Karl Hasselström <kha@treskal.com>

diff --git a/stgit/lib/transaction.py b/stgit/lib/transaction.py
index 2946a67840be7c63fa90a9d5e233b567f30dbe26..1ece01ea3e55996d8ccb82351a85b016d58fa865 100644 (file)
--- a/stgit/lib/transaction.py
+++ b/stgit/lib/transaction.py
@@ -1,4 +1,5 @@
 from stgit import exception, utils
 from stgit import exception, utils

+from stgit.utils import any, all

 from stgit.out import *
 from stgit.lib import git
 
 from stgit.out import *
 from stgit.lib import git
 


@@ -175,8 +176,8 @@ class StackTransaction(object):
         """Attempt to push the named patch. If this results in conflicts,
         halts the transaction. If index+worktree are given, spill any
         conflicts to them."""
         """Attempt to push the named patch. If this results in conflicts,
         halts the transaction. If index+worktree are given, spill any
         conflicts to them."""

-        cd = self.patches[pn].data
-        cd = cd.set_committer(None)
+        orig_cd = self.patches[pn].data
+        cd = orig_cd.set_committer(None)

         s = ['', ' (empty)'][cd.is_nochange()]
         oldparent = cd.parent
         cd = cd.set_parent(self.__head)
         s = ['', ' (empty)'][cd.is_nochange()]
         oldparent = cd.parent
         cd = cd.set_parent(self.__head)


@@ -204,7 +205,11 @@ class StackTransaction(object):
             except git.MergeException, e:
                 self.__halt(str(e))
         cd = cd.set_tree(tree)
             except git.MergeException, e:
                 self.__halt(str(e))
         cd = cd.set_tree(tree)

-        self.patches[pn] = self.__stack.repository.commit(cd)
+        if any(getattr(cd, a) != getattr(orig_cd, a) for a in
+               ['parent', 'tree', 'author', 'message']):
+            self.patches[pn] = self.__stack.repository.commit(cd)
+        else:
+            s = ' (unmodified)'

         del self.unapplied[self.unapplied.index(pn)]
         self.applied.append(pn)
         out.info('Pushed %s%s' % (pn, s))
         del self.unapplied[self.unapplied.index(pn)]
         self.applied.append(pn)
         out.info('Pushed %s%s' % (pn, s))