diff -r 108b08a16260 -r 2cbb9914d227 tests/test-evolve.t
--- a/tests/test-evolve.t	Mon Dec 24 17:47:27 2018 +0100
+++ b/tests/test-evolve.t	Tue Jan 22 12:54:43 2019 -0500
@@ -1590,3 +1590,110 @@
   
   x  0:f7ad41964313 added a ()
   
+  $ cd ..
+
+Test which shows that orphanmerge evolution can result to crash because of
+lastsolved not being updated in case of orphanmerge:
+(It will be fixed in next patch)
+
+Prepare the repo:
+  $ hg init orphanmergerepo
+  $ cd orphanmergerepo
+  $ echo a > a
+  $ for fn in a b c; do echo foo > $fn; hg ci -Am "added "$fn; done;
+  adding a
+  adding b
+  adding c
+Lets create a merge commit so that we can create orhpan merge later:
+  $ hg up 1 -q
+  $ echo feature > f
+  $ hg ci -Am "added feature f"
+  adding f
+  created new head
+  $ hg merge
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  (branch merge, don't forget to commit)
+  $ hg ci -m "merge feature branch"
+  $ glog
+  @    4:2c0a98d38026@default(draft) merge feature branch
+  |\
+  | o  3:4c33e511041e@default(draft) added feature f
+  | |
+  o |  2:8be98ac1a569@default(draft) added c
+  |/
+  o  1:80e6d2c47cfe@default(draft) added b
+  |
+  o  0:f7ad41964313@default(draft) added a
+  
+
+Now make the parents of merge commit obsolete to get a orphan merge:
+  $ hg up 2 -q
+  $ echo "fixit" > c
+  $ hg ci --amend -m "updated c"
+  1 new orphan changesets
+  $ hg up 3 -q
+  $ echo "fixit" > c
+  $ hg ci --amend -m "updated f"
+  $ glog
+  @  6:086d9bedcd75@default(draft) updated f
+  |
+  | o  5:f84f2c548fbc@default(draft) updated c
+  |/
+  | *    4:2c0a98d38026@default(draft) merge feature branch
+  | |\
+  +---x  3:4c33e511041e@default(draft) added feature f
+  | |
+  | x  2:8be98ac1a569@default(draft) added c
+  |/
+  o  1:80e6d2c47cfe@default(draft) added b
+  |
+  o  0:f7ad41964313@default(draft) added a
+  
+
+To check `lastsolved` contain right value after completion of orphan-merge
+resolution there should be one more trouble to be evolved; lets create one:
+  $ hg up 1 -q
+  $ echo d > d
+  $ hg ci -Am "added d"
+  adding c
+  adding d
+  created new head
+  $ echo e > e
+  $ hg ci -Am "added e"
+  adding e
+  $ hg up .^
+  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  $ echo "updated d" >> d
+  $ hg ci --amend -m "updated d"
+  1 new orphan changesets
+  $ glog
+  @  9:7c4d1834c346@default(draft) updated d
+  |
+  | *  8:421f7614462a@default(draft) added e
+  | |
+  | x  7:afe5acea1990@default(draft) added d
+  |/
+  | o  6:086d9bedcd75@default(draft) updated f
+  |/
+  | o  5:f84f2c548fbc@default(draft) updated c
+  |/
+  | *    4:2c0a98d38026@default(draft) merge feature branch
+  | |\
+  +---x  3:4c33e511041e@default(draft) added feature f
+  | |
+  | x  2:8be98ac1a569@default(draft) added c
+  |/
+  o  1:80e6d2c47cfe@default(draft) added b
+  |
+  o  0:f7ad41964313@default(draft) added a
+  
+Now we have one orphan merge and one more orphan cset that we just created.
+Lets evolve:
+  $ hg evolve --all --any
+  move:[4] merge feature branch
+  atop:[5] updated c
+  move:[10] merge feature branch
+  atop:[6] updated f
+  move:[8] added e
+  atop:[9] updated d
+  working directory is now at 7c67cee06242