--- 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:

--- a/mercurial/interfaces/repository.py	Wed Sep 16 21:00:02 2020 +0200
+++ b/mercurial/interfaces/repository.py	Thu Oct 01 09:29:49 2020 +0200
@@ -28,12 +28,14 @@
 REVISION_FLAG_ELLIPSIS = 1 << 14
 REVISION_FLAG_EXTSTORED = 1 << 13
 REVISION_FLAG_SIDEDATA = 1 << 12
+REVISION_FLAG_HASCOPIESINFO = 1 << 11
 
 REVISION_FLAGS_KNOWN = (
     REVISION_FLAG_CENSORED
     | REVISION_FLAG_ELLIPSIS
     | REVISION_FLAG_EXTSTORED
     | REVISION_FLAG_SIDEDATA
+    | REVISION_FLAG_HASCOPIESINFO
 )
 
 CG_DELTAMODE_STD = b'default'

--- a/mercurial/revlog.py	Wed Sep 16 21:00:02 2020 +0200
+++ b/mercurial/revlog.py	Thu Oct 01 09:29:49 2020 +0200
@@ -53,6 +53,7 @@
     REVIDX_ELLIPSIS,
     REVIDX_EXTSTORED,
     REVIDX_FLAGS_ORDER,
+    REVIDX_HASCOPIESINFO,
     REVIDX_ISCENSORED,
     REVIDX_RAWTEXT_CHANGING_FLAGS,
     REVIDX_SIDEDATA,
@@ -98,6 +99,7 @@
 REVIDX_ISCENSORED
 REVIDX_ELLIPSIS
 REVIDX_SIDEDATA
+REVIDX_HASCOPIESINFO
 REVIDX_EXTSTORED
 REVIDX_DEFAULT_FLAGS
 REVIDX_FLAGS_ORDER

--- a/mercurial/revlogutils/constants.py	Wed Sep 16 21:00:02 2020 +0200
+++ b/mercurial/revlogutils/constants.py	Thu Oct 01 09:29:49 2020 +0200
@@ -40,6 +40,8 @@
 REVIDX_EXTSTORED = repository.REVISION_FLAG_EXTSTORED
 # revision data contains extra metadata not part of the official digest
 REVIDX_SIDEDATA = repository.REVISION_FLAG_SIDEDATA
+# revision changes files in a way that could affect copy tracing.
+REVIDX_HASCOPIESINFO = repository.REVISION_FLAG_HASCOPIESINFO
 REVIDX_DEFAULT_FLAGS = 0
 # stable order in which flags need to be processed and their processors applied
 REVIDX_FLAGS_ORDER = [
@@ -47,6 +49,7 @@
     REVIDX_ELLIPSIS,
     REVIDX_EXTSTORED,
     REVIDX_SIDEDATA,
+    REVIDX_HASCOPIESINFO,
 ]
 
 # bitmark for flags that could cause rawdata content change

--- a/mercurial/revlogutils/flagutil.py	Wed Sep 16 21:00:02 2020 +0200
+++ b/mercurial/revlogutils/flagutil.py	Thu Oct 01 09:29:49 2020 +0200
@@ -15,6 +15,7 @@
     REVIDX_ELLIPSIS,
     REVIDX_EXTSTORED,
     REVIDX_FLAGS_ORDER,
+    REVIDX_HASCOPIESINFO,
     REVIDX_ISCENSORED,
     REVIDX_RAWTEXT_CHANGING_FLAGS,
     REVIDX_SIDEDATA,
@@ -28,6 +29,7 @@
 REVIDX_ELLIPSIS
 REVIDX_EXTSTORED
 REVIDX_SIDEDATA
+REVIDX_HASCOPIESINFO,
 REVIDX_DEFAULT_FLAGS
 REVIDX_FLAGS_ORDER
 REVIDX_RAWTEXT_CHANGING_FLAGS
@@ -37,6 +39,7 @@
 # Store flag processors (cf. 'addflagprocessor()' to register)
 flagprocessors = {
     REVIDX_ISCENSORED: None,
+    REVIDX_HASCOPIESINFO: None,
 }
 
 

--- a/tests/test-lfs-serve.t	Wed Sep 16 21:00:02 2020 +0200
+++ b/tests/test-lfs-serve.t	Thu Oct 01 09:29:49 2020 +0200
@@ -360,9 +360,11 @@
   # LFS required- both lfs and non-lfs revlogs have 0x2000 flag
   *** runcommand debugprocessors lfs.bin -R ../server
   registered processor '0x8000'
+  registered processor '0x800'
   registered processor '0x2000'
   *** runcommand debugprocessors nonlfs2.txt -R ../server
   registered processor '0x8000'
+  registered processor '0x800'
   registered processor '0x2000'
   *** runcommand config extensions --cwd ../server
   extensions.debugprocessors=$TESTTMP/debugprocessors.py
@@ -371,6 +373,7 @@
   # LFS not enabled- revlogs don't have 0x2000 flag
   *** runcommand debugprocessors nonlfs3.txt
   registered processor '0x8000'
+  registered processor '0x800'
   *** runcommand config extensions
   extensions.debugprocessors=$TESTTMP/debugprocessors.py
 
@@ -413,9 +416,11 @@
   # LFS enabled- both lfs and non-lfs revlogs have 0x2000 flag
   *** runcommand debugprocessors lfs.bin -R ../server
   registered processor '0x8000'
+  registered processor '0x800'
   registered processor '0x2000'
   *** runcommand debugprocessors nonlfs2.txt -R ../server
   registered processor '0x8000'
+  registered processor '0x800'
   registered processor '0x2000'
   *** runcommand config extensions --cwd ../server
   extensions.debugprocessors=$TESTTMP/debugprocessors.py
@@ -424,6 +429,7 @@
   # LFS enabled without requirement- revlogs have 0x2000 flag
   *** runcommand debugprocessors nonlfs3.txt
   registered processor '0x8000'
+  registered processor '0x800'
   registered processor '0x2000'
   *** runcommand config extensions
   extensions.debugprocessors=$TESTTMP/debugprocessors.py
@@ -432,6 +438,7 @@
   # LFS disabled locally- revlogs don't have 0x2000 flag
   *** runcommand debugprocessors nonlfs.txt -R ../nonlfs
   registered processor '0x8000'
+  registered processor '0x800'
   *** runcommand config extensions --cwd ../nonlfs
   extensions.debugprocessors=$TESTTMP/debugprocessors.py
   extensions.lfs=!