cleanup: run pyupgrade on our source tree to clean up varying things Built with: hg files 'set:**.py - mercurial/thirdparty/** - "contrib/python-zstandard/**" - hgext/fsmonitor/pywatchman/**' | xargs pyupgrade --keep-percent-format --keep-extraneous-parens and then blackened. pyupgrade comes from https://github.com/asottile/pyupgrade with a patch to let me preserve extraneous parens (which we use for marking strings that shouldn't be translated), and lets us clean up a bunch of idioms that have cruftily accumulated over the years. # skip-blame no-op automated code cleanups Differential Revision: https://phab.mercurial-scm.org/D8255

--- a/mercurial/patch.py	Fri Mar 06 10:52:44 2020 +0100
+++ b/mercurial/patch.py	Fri Mar 06 13:27:41 2020 -0500
@@ -2888,7 +2888,7 @@
     or 'rename' (the latter two only if opts.git is set).'''
     gone = set()
 
-    copyto = dict([(v, k) for k, v in copy.items()])
+    copyto = {v: k for k, v in copy.items()}
 
     addedset, removedset = set(added), set(removed)