narrow: reuse narrowspec.updateworkingcopy() when narrowing

narrow: reuse narrowspec.updateworkingcopy() when narrowing

Similar to the previous patch for widening, but here we also need to
teach updateworkingcopy() to forcefully delete files that are not
recorded in the dirstate as clean. That should be safe because the
narrowing command (e.g. `hg tracked --removeinclude`) has already
checked that the working copy is clean.

Differential Revision: https://phab.mercurial-scm.org/D5511

--- a/hgext/narrow/narrowcommands.py	Fri Dec 21 10:05:37 2018 -0800
+++ b/hgext/narrow/narrowcommands.py	Sun Dec 30 00:15:38 2018 -0800
@@ -159,16 +159,6 @@
 extensions.wrapfunction(exchange,'_pullbundle2extraprepare',
                         pullbundle2extraprepare)
 
-# This is an extension point for filesystems that need to do something other
-# than just blindly unlink the files. It's not clear what arguments would be
-# useful, so we're passing in a fair number of them, some of them redundant.
-def _narrowcleanupwdir(repo, oldincludes, oldexcludes, newincludes, newexcludes,
-                       oldmatch, newmatch):
-    for f in repo.dirstate:
-        if not newmatch(f):
-            repo.dirstate.drop(f)
-            repo.wvfs.unlinkpath(f)
-
 def _narrow(ui, repo, remote, commoninc, oldincludes, oldexcludes,
             newincludes, newexcludes, force):
     oldmatch = narrowspec.match(repo.root, oldincludes, oldexcludes)
@@ -240,19 +230,18 @@
 
         repo.destroying()
 
-        with repo.transaction("narrowing"):
+        with repo.transaction('narrowing'):
             # Update narrowspec before removing revlogs, so repo won't be
             # corrupt in case of crash
             repo.setnarrowpats(newincludes, newexcludes)
-            narrowspec.copytoworkingcopy(repo)
 
             for f in todelete:
                 ui.status(_('deleting %s\n') % f)
                 util.unlinkpath(repo.svfs.join(f))
                 repo.store.markremoved(f)
 
-            _narrowcleanupwdir(repo, oldincludes, oldexcludes, newincludes,
-                               newexcludes, oldmatch, newmatch)
+            narrowspec.updateworkingcopy(repo, assumeclean=True)
+            narrowspec.copytoworkingcopy(repo)
 
         repo.destroyed()
 

--- a/mercurial/narrowspec.py	Fri Dec 21 10:05:37 2018 -0800
+++ b/mercurial/narrowspec.py	Sun Dec 30 00:15:38 2018 -0800
@@ -273,7 +273,12 @@
         raise error.Abort(_("working copy's narrowspec is stale"),
                           hint=_("run 'hg tracked --update-working-copy'"))
 
-def updateworkingcopy(repo):
+def updateworkingcopy(repo, assumeclean=False):
+    """updates the working copy and dirstate from the store narrowspec
+
+    When assumeclean=True, files that are not known to be clean will also
+    be deleted. It is then up to the caller to make sure they are clean.
+    """
     oldspec = repo.vfs.tryread(DIRSTATE_FILENAME)
     newspec = repo.svfs.tryread(FILENAME)
 
@@ -287,11 +292,17 @@
     ds = repo.dirstate
     lookup, status = ds.status(removedmatch, subrepos=[], ignored=False,
                                clean=True, unknown=False)
-    _deletecleanfiles(repo, status.clean)
-    trackeddirty = lookup + status.modified + status.added
+    trackeddirty = status.modified + status.added
+    clean = status.clean
+    if assumeclean:
+        assert not trackeddirty
+        clean.extend(lookup)
+    else:
+        trackeddirty.extend(lookup)
+    _deletecleanfiles(repo, clean)
     for f in sorted(trackeddirty):
         repo.ui.status(_('not deleting possibly dirty file %s\n') % f)
-    for f in status.clean + trackeddirty:
+    for f in clean + trackeddirty:
         ds.drop(f)
 
     repo.narrowpats = newincludes, newexcludes