--- a/hgext3rd/evolve/__init__.py	Fri Jun 08 18:32:48 2018 +0530
+++ b/hgext3rd/evolve/__init__.py	Fri Jun 08 17:36:28 2018 +0530
@@ -966,15 +966,21 @@
 def _getcurrenttopic(repo):
     return getattr(repo, 'currenttopic', '')
 
-def _prevupdate(repo, displayer, target, bookmark, dryrun):
+def _prevupdate(repo, displayer, target, bookmark, dryrun, mergeopt):
     if dryrun:
         repo.ui.write(_('hg update %s;\n') % target)
         if bookmark is not None:
             repo.ui.write(_('hg bookmark %s -r %s;\n')
                           % (bookmark, target))
     else:
+        updatecheck = None
+        # --merge is passed, we don't need to care about commands.update.check
+        # config option
+        if mergeopt:
+            updatecheck = 'none'
         try:
-            ret = hg.updatetotally(repo.ui, repo, target.node(), None)
+            ret = hg.updatetotally(repo.ui, repo, target.node(), None,
+                                   updatecheck=updatecheck)
         except error.Abort as exc:
             # replace the hint to mention about --merge option
             exc.hint = _('do you want --merge?')
@@ -1047,6 +1053,7 @@
     Displays the summary line of the destination for clarity."""
     wlock = None
     dryrunopt = opts['dry_run']
+    mergeopt = opts['merge']
     if not dryrunopt:
         wlock = repo.wlock()
     try:
@@ -1054,7 +1061,7 @@
         wparents = wkctx.parents()
         if len(wparents) != 1:
             raise error.Abort(_('merge in progress'))
-        if not opts['merge']:
+        if not mergeopt:
             # we only skip the check if noconflict is set
             if ui.config('commands', 'update.check') == 'noconflict':
                 pass
@@ -1077,7 +1084,8 @@
                 if topic and _getcurrenttopic(repo) != _gettopic(target):
                     repo.ui.setconfig('_internal', 'keep-topic', 'yes',
                                       source='topic-extension')
-                _prevupdate(repo, displayer, target, bookmark, dryrunopt)
+                _prevupdate(repo, displayer, target, bookmark, dryrunopt,
+                            mergeopt)
             finally:
                 repo.ui.restoreconfig(backup)
             return 0
@@ -1213,8 +1221,14 @@
         if shouldmove:
             ui.write(_('hg bookmark %s -r %s;\n') % (bm, children))
     else:
+        updatecheck = None
+        # --merge is passed, we don't need to care about commands.update.check
+        # config option
+        if opts['merge']:
+            updatecheck = 'none'
         try:
-            ret = hg.updatetotally(ui, repo, children.node(), None)
+            ret = hg.updatetotally(ui, repo, children.node(), None,
+                                   updatecheck=updatecheck)
         except error.Abort as exc:
             # replace the hint to mention about --merge option
             exc.hint = _('do you want --merge?')

--- a/tests/test-prev-next.t	Fri Jun 08 18:32:48 2018 +0530
+++ b/tests/test-prev-next.t	Fri Jun 08 17:36:28 2018 +0530
@@ -446,26 +446,38 @@
   $ echo hi > bar
   $ echo bar >> bar
   $ hg next --merge
-  abort: conflicting changes
-  (do you want --merge?)
-  [255]
+  merging bar
+  warning: conflicts while merging bar! (edit, then use 'hg resolve --mark')
+  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
+  use 'hg resolve' to retry unresolved file merges
+  [2] added bar
+
+  $ echo babar > bar
+  $ hg resolve -m
+  (no more unresolved files)
 
 Testing --merge works with other values of commands.update.check also
 
 XXX: things are broken!
   $ hg prev --merge --config commands.update.check=abort
-  abort: uncommitted changes
-  (do you want --merge?)
-  [255]
+  local [working copy] changed bar which other [destination] deleted
+  use (c)hanged version, (d)elete, or leave (u)nresolved? 
+  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
+  use 'hg resolve' to retry unresolved file merges
+  [1] added foo
 
   $ hg revert --all
   forgetting bar
   reverting wat
+  $ hg resolve -m
+  (no more unresolved files)
 
   $ echo bar > bar
   $ hg add bar
 
   $ hg next --merge --config commands.update.check=abort
-  abort: uncommitted changes
-  (do you want --merge?)
-  [255]
+  merging bar
+  warning: conflicts while merging bar! (edit, then use 'hg resolve --mark')
+  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
+  use 'hg resolve' to retry unresolved file merges
+  [2] added bar