--- a/hgext/rebase.py	Mon May 29 18:41:58 2023 +0200
+++ b/hgext/rebase.py	Thu May 25 00:23:05 2023 +0200
@@ -24,7 +24,6 @@
     wdirrev,
 )
 from mercurial.pycompat import open
-from mercurial.thirdparty.jaraco.collections import Projection
 from mercurial import (
     bookmarks,
     cmdutil,
@@ -86,19 +85,6 @@
     return 1
 
 
-def retained_extras():
-    """
-    Yield the names of the extras to be retained.
-    """
-    # graft
-    yield b'source'
-    yield b'intermediate-source'
-
-
-def _save_extras(ctx, extra):
-    extra.update(Projection(retained_extras(), ctx.extra()))
-
-
 def _savebranch(ctx, extra):
     extra[b'branch'] = ctx.branch()
 
@@ -199,7 +185,7 @@
         self.date = opts.get('date', None)
 
         e = opts.get('extrafn')  # internal, used by e.g. hgsubversion
-        self.extrafns = [_save_extras]
+        self.extrafns = [rewriteutil.preserve_extras_on_rebase]
         if e:
             self.extrafns = [e]