diff --git a/tests/test-copies-chain-merge.t b/tests/test-copies-chain-merge.t
--- a/tests/test-copies-chain-merge.t
+++ b/tests/test-copies-chain-merge.t
@@ -999,6 +999,8 @@
 does not involve the file 'f' and the arbitration done within "mAEm" and "mEA"
 about that file should stay unchanged.
 
+We also touch J during some of the merge to check for unrelated change to new file during merge.
+
   $ case_desc="chained merges (conflict -> simple) - same content everywhere"
 
 (extra unrelated changes)
@@ -1048,17 +1050,19 @@
   $ hg merge 'desc("j-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
+  $ echo jj > unrelated-j
   $ hg ci -m "mEA,Jm: $case_desc"
 
 (merge variant 4)
 
   $ hg up 'desc("j-1")'
-  2 files updated, 0 files merged, 0 files removed, 0 files unresolved (no-changeset !)
-  1 files updated, 0 files merged, 0 files removed, 0 files unresolved (changeset !)
+  3 files updated, 0 files merged, 0 files removed, 0 files unresolved (no-changeset !)
+  2 files updated, 0 files merged, 0 files removed, 0 files unresolved (changeset !)
   $ hg merge 'desc("mEAm")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved (no-changeset !)
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved (changeset !)
   (branch merge, don't forget to commit)
+  $ echo jj > unrelated-j
   $ hg ci -m "mJ,EAm: $case_desc"
   created new head
 
@@ -1941,12 +1945,22 @@
     '\x00\x00\x00\x00'
   ##### revision "mEA,Jm" #####
   1 sidedata entries
-   entry-0014 size 4
-    '\x00\x00\x00\x00'
+   entry-0014 size 24
+    '\x00\x00\x00\x01\x14\x00\x00\x00\x0b\x00\x00\x00\x00unrelated-j' (no-upgraded no-upgraded-parallel !)
+  touched    : unrelated-j, ; (no-upgraded no-upgraded-parallel !)
+    '\x00\x00\x00\x01\x08\x00\x00\x00\x0b\x00\x00\x00\x00unrelated-j' (upgraded known-bad-output !)
+  merged     : unrelated-j, ; (upgraded known-bad-output !)
+    '\x00\x00\x00\x01\x08\x00\x00\x00\x0b\x00\x00\x00\x00unrelated-j' (upgraded-parallel known-bad-output !)
+  merged     : unrelated-j, ; (upgraded-parallel known-bad-output !)
   ##### revision "mJ,EAm" #####
   1 sidedata entries
-   entry-0014 size 4
-    '\x00\x00\x00\x00'
+   entry-0014 size 24
+    '\x00\x00\x00\x01\x14\x00\x00\x00\x0b\x00\x00\x00\x00unrelated-j' (no-upgraded no-upgraded-parallel !)
+  touched    : unrelated-j, ; (no-upgraded no-upgraded-parallel !)
+    '\x00\x00\x00\x01\x08\x00\x00\x00\x0b\x00\x00\x00\x00unrelated-j' (upgraded known-bad-output !)
+  merged     : unrelated-j, ; (upgraded known-bad-output !)
+    '\x00\x00\x00\x01\x08\x00\x00\x00\x0b\x00\x00\x00\x00unrelated-j' (upgraded-parallel known-bad-output !)
+  merged     : unrelated-j, ; (upgraded-parallel known-bad-output !)
   ##### revision "s-1" #####
   1 sidedata entries
    entry-0014 size 24