copies: add an devel option to trace all files Filelog based copy tracing only trace copy for file that have been added. This is a trade off between skipping some rare copy case in exchange for avoiding atrocious-to-the-point-of-unusable performance. The changeset centric copy tracing does not need this trade off and naturally trace all copy, include the one involving non-new files. In order to ease the comparison from both algorithm, we add a small devel option to trace copy for all files in the target revisions. Differential Revision: https://phab.mercurial-scm.org/D9796

--- a/mercurial/configitems.py	Thu Jan 28 15:26:33 2021 +0100
+++ b/mercurial/configitems.py	Sat Jan 16 00:03:18 2021 +0100
@@ -615,6 +615,12 @@
     b'check-relroot',
     default=False,
 )
+# Track copy information for all file, not just "added" one (very slow)
+coreconfigitem(
+    b'devel',
+    b'copy-tracing.trace-all-files',
+    default=False,
+)
 coreconfigitem(
     b'devel',
     b'default-date',