diff -r 6db55f28c965 -r fcc467ca740e hgext/evolve.py
--- a/hgext/evolve.py	Tue Jun 23 15:32:47 2015 -0700
+++ b/hgext/evolve.py	Tue Jun 23 15:26:51 2015 -0700
@@ -1950,7 +1950,8 @@
 
 @command('^previous',
          [('B', 'move-bookmark', False,
-             _('Move active bookmark after update'))],
+             _('Move active bookmark after update')),
+          ('', 'merge', False, _('bring uncommited change along'))],
          '[-B]')
 def cmdprevious(ui, repo, **opts):
     """update to parent and display summary lines"""
@@ -1958,6 +1959,12 @@
     wparents = wkctx.parents()
     if len(wparents) != 1:
         raise util.Abort('merge in progress')
+    if not opts['merge']:
+        try:
+            cmdutil.bailifchanged(repo)
+        except error.Abort, exc:
+            exc.hint = _('do you want --merge?')
+            raise
 
     parents = wparents[0].parents()
     displayer = cmdutil.show_changeset(ui, repo, {'template': shorttemplate})
@@ -1982,7 +1989,8 @@
 
 @command('^next',
          [('B', 'move-bookmark', False,
-             _('Move active bookmark after update'))],
+             _('Move active bookmark after update')),
+          ('', 'merge', False, _('bring uncommited change along'))],
          '[-B]')
 def cmdnext(ui, repo, **opts):
     """update to child and display summary lines"""
@@ -1990,6 +1998,12 @@
     wparents = wkctx.parents()
     if len(wparents) != 1:
         raise util.Abort('merge in progress')
+    if not opts['merge']:
+        try:
+            cmdutil.bailifchanged(repo)
+        except error.Abort, exc:
+            exc.hint = _('do you want --merge?')
+            raise
 
     children = [ctx for ctx in wparents[0].children() if not ctx.obsolete()]
     displayer = cmdutil.show_changeset(ui, repo, {'template': shorttemplate})