diff mercurial/changelog.py @ 45671:2d6aea053153

copies: add a HASCOPIESINFO flag to highlight rev with useful data

If some files changes that may impact copy tracing are detected, we set this
flag. This helps the copy tracing algorithm to skip fetching possibly expensive
data when unnecessary.

Differential Revision: https://phab.mercurial-scm.org/D9139

--- a/mercurial/changelog.py	Wed Sep 16 21:00:02 2020 +0200
+++ b/mercurial/changelog.py	Thu Oct 01 09:29:49 2020 +0200
@@ -26,6 +26,7 @@
     dateutil,
     stringutil,
 )
+from .revlogutils import flagutil
 
 _defaultextra = {b'branch': b'default'}
 
@@ -579,8 +580,17 @@
                     _(b'the name \'%s\' is reserved') % branch
                 )
         sortedfiles = sorted(files.touched)
+        flags = 0
         sidedata = None
         if self._copiesstorage == b'changeset-sidedata':
+            if (
+                files.removed
+                or files.merged
+                or files.salvaged
+                or files.copied_from_p1
+                or files.copied_from_p2
+            ):
+                flags |= flagutil.REVIDX_HASCOPIESINFO
             sidedata = metadata.encode_files_sidedata(files)
 
         if extra: