diff -r 8b6e2565aaf3 -r d31d39ea0fe4 tests/test-evolve-issue5958.t
--- a/tests/test-evolve-issue5958.t	Tue Dec 10 19:13:06 2019 +0100
+++ b/tests/test-evolve-issue5958.t	Tue Dec 10 19:27:55 2019 +0100
@@ -22,6 +22,8 @@
 (Make changes in unrelated files so that we don't have any merge conflicts
 during the rebase, but the two touched revisions aren't identical)
 
+date: updated on both side to the same value
+
   $ echo hi > bar.txt
   $ hg add -q bar.txt
   $ hg amend -q
@@ -99,3 +101,59 @@
   4 c17bf400a278 1969-12-31 23:59 -0000: rewritten using evolve as 7:2372e6d39855
   7 2372e6d39855 1970-01-01 00:00 +0000: 
   7 bb2424887202 1969-12-31 23:59 +0000: (false !)
+
+date: updated one one side to an older value
+
+  $ hg evolve -r .
+  move:[7] add foo.txt
+  atop:[0] add r0
+  working directory is now at 2b9788beff53
+  $ hg update --hidden --rev 'predecessors(.)'
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to hidden changeset 2372e6d39855
+  (hidden revision '2372e6d39855' was rewritten as: 2b9788beff53)
+  working directory parent is obsolete! (2372e6d39855)
+  (use 'hg evolve' to update to its successor: 2b9788beff53)
+  $ hg amend --date "0 2"
+  1 new orphan changesets
+  2 new content-divergent changesets
+  $ hg rebase -r . -d 0
+  rebasing 9:88085147662e "add foo.txt" (tip)
+  $ hg log -G
+  @  changeset:   10:873d828420d8
+  |  tag:         tip
+  |  parent:      0:a24ed8ad918c
+  |  user:        test
+  |  date:        Wed Dec 31 23:59:58 1969 -0000
+  |  instability: content-divergent
+  |  summary:     add foo.txt
+  |
+  | *  changeset:   8:2b9788beff53
+  |/   parent:      0:a24ed8ad918c
+  |    user:        test
+  |    date:        Thu Jan 01 00:00:00 1970 +0000
+  |    instability: content-divergent
+  |    summary:     add foo.txt
+  |
+  o  changeset:   0:a24ed8ad918c
+     user:        test
+     date:        Thu Jan 01 00:00:00 1970 +0000
+     summary:     add r0
+  
+  $ hg evolve --list -r .
+  873d828420d8: add foo.txt
+    content-divergent: 2b9788beff53 (draft) (precursor 2372e6d39855)
+  
+  $ hg log -r 2372e6d39855+873d828420d8+2b9788beff53 --hidden -T '{rev} {node|short} {date|isodate}: {join(obsfate, "; ")}\n'
+  7 2372e6d39855 1970-01-01 00:00 +0000: date-changed using amend as 9:88085147662e; rebased using evolve as 8:2b9788beff53
+  10 873d828420d8 1969-12-31 23:59 -0000: 
+  8 2b9788beff53 1970-01-01 00:00 +0000: 
+  $ hg evolve --content-divergent
+  merge:[8] add foo.txt
+  with: [10] add foo.txt
+  base: [7] add foo.txt
+  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  working directory is now at bb2424887202
+  $ hg log -r . --hidden -T '{rev} {node|short} {date|isodate}: {join(obsfate, "; ")}\n'
+  11 bb2424887202 1970-01-01 00:00 +0000: 
+  11 bb2424887202 1969-12-31 23:59 +0000: (false !)