strip: properly clear resolve state with --keep (issue4593)

Normal updates automatically clean up the resolve state, but strip
--keep does a "manual" update that bypasses the normal machinery. This
adds a mergestate reset.

hgext/strip.py

@@ -7,7 +7,7 b' from mercurial.i18n import _'
 from mercurial.node import nullid
 from mercurial.lock import release
 from mercurial import cmdutil, hg, scmutil, util
-from mercurial import repair, bookmarks
+from mercurial import repair, bookmarks, merge
 
 cmdtable = {}
 command = cmdutil.command(cmdtable)
@@ -205,6 +205,11 b' def stripcmd(ui, repo, *revs, **opts):'
 
             repo.dirstate.rebuild(urev, uctx.manifest(), changedfiles)
             repo.dirstate.write()
+
+            # clear resolve state
+            ms = merge.mergestate(repo)
+            ms.reset(repo['.'].node())
+
             update = False
 
 

tests/test-strip.t

@@ -496,10 +496,11 b' applied patches after stripping ancestor'
 Verify strip protects against stripping wc parent when there are uncommitted mods
 
   $ echo b > b
+  $ echo bb > bar
   $ hg add b
   $ hg ci -m 'b'
   $ hg log --graph
-  @  changeset:   1:7519abd79d14
+  @  changeset:   1:76dcf9fab855
   |  tag:         tip
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
@@ -510,9 +511,24 b' Verify strip protects against stripping '
      date:        Thu Jan 01 00:00:00 1970 +0000
      summary:     a
   
+  $ hg up 0
+  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  $ echo c > bar
+  $ hg up -t false
+  merging bar
+  merging bar failed!
+  1 files updated, 0 files merged, 0 files removed, 1 files unresolved
+  use 'hg resolve' to retry unresolved file merges
+  [1]
+  $ hg sum
+  parent: 1:76dcf9fab855 tip
+   b
+  branch: default
+  commit: 1 modified, 1 unknown, 1 unresolved
+  update: (current)
+  mq:     3 unapplied
 
   $ echo c > b
-  $ echo c > bar
   $ hg strip tip
   abort: local changes found
   [255]
@@ -528,6 +544,16 b' Verify strip protects against stripping '
   $ hg status
   M bar
   ? b
+  ? bar.orig
+
+  $ rm bar.orig
+  $ hg sum
+  parent: 0:9ab35a2d17cb tip
+   a
+  branch: default
+  commit: 1 modified, 1 unknown
+  update: (current)
+  mq:     3 unapplied
 
 Strip adds, removes, modifies with --keep