narrow: consider both local and remote matchers in narrowchangegroup

The existing code that picked one or the other seemed very
suspicious. This patch makes us intersect the local matcher with the
matcher from the remote, which seems better. It fixes one test case
and makes another one that used to crash no longer crash, but instead
silently succeed with a push that's lossy, so that remains to be
fixed.

The real reason for doing this now is that I'm going to move
narrowrepo.narrowmatch() onto localrepo and then it will always be
defined, which would otherwise break this code.

Differential Revision: https://phab.mercurial-scm.org/D2490

hgext/narrow/narrowchangegroup.py

@@ -13,6 +13,7 b' from mercurial import ('
     error,
     extensions,
     manifest,
+    match as matchmod,
     mdiff,
     node,
     revlog,
@@ -21,12 +22,19 b' from mercurial import ('
 
 def setup():
 
+    def _cgmatcher(cgpacker):
+        localmatcher = getattr(cgpacker._repo, 'narrowmatch', lambda: None)()
+        remotematcher = getattr(cgpacker, '_narrow_matcher', lambda: None)()
+        if localmatcher and remotematcher:
+            return matchmod.intersectmatchers(localmatcher, remotematcher)
+        else:
+            return localmatcher or remotematcher
+
     def prune(orig, self, revlog, missing, commonrevs):
         if isinstance(revlog, manifest.manifestrevlog):
-            matcher = getattr(self._repo, 'narrowmatch',
-                              getattr(self, '_narrow_matcher', None))
-            if (matcher is not None and
-                not matcher().visitdir(revlog._dir[:-1] or '.')):
+            matcher = _cgmatcher(self)
+            if (matcher and
+                not matcher.visitdir(revlog._dir[:-1] or '.')):
                 return []
         return orig(self, revlog, missing, commonrevs)
 
@@ -34,11 +42,9 b' def setup():'
 
     def generatefiles(orig, self, changedfiles, linknodes, commonrevs,
                       source):
-        matcher = getattr(self._repo, 'narrowmatch',
-                          getattr(self, '_narrow_matcher', None))
-        if matcher is not None:
-            narrowmatch = matcher()
-            changedfiles = [f for f in changedfiles if narrowmatch(f)]
+        matcher = _cgmatcher(self)
+        if matcher:
+            changedfiles = filter(matcher, changedfiles)
         if getattr(self, 'is_shallow', False):
             # See comment in generate() for why this sadness is a thing.
             mfdicts = self._mfdicts

tests/test-narrow-exchange.t

@@ -137,13 +137,12 b' narrow spec'
   $ hg pull ssh://user@dummy/narrow2
   pulling from ssh://user@dummy/narrow2
   searching for changes
-  remote: abort: unable to resolve parent while packing 'data/inside2/f.i' 3 for changeset 5 (?)
   adding changesets
-  remote: abort: unexpected error: unable to resolve parent while packing 'data/inside2/f.i' 3 for changeset 5
-  transaction abort!
-  rollback completed
-  abort: pull failed on remote
-  [255]
+  adding manifests
+  adding file changes
+  added 1 changesets with 0 changes to 0 files
+  new changesets d78a96df731d
+  (run 'hg update' to get a working copy)
 
 Check that the resulting history is valid in the full repo
 
@@ -204,7 +203,7 b' necessary content to be able to push to '
   $ hg push ssh://user@dummy/narrow2
   pushing to ssh://user@dummy/narrow2
   searching for changes
-  remote has heads on branch 'default' that are not known locally: d78a96df731d
-  abort: push creates new remote head 5970befb64ba!
-  (pull and merge or see 'hg help push' for details about pushing new heads)
-  [255]
+  remote: adding changesets
+  remote: adding manifests
+  remote: adding file changes
+  remote: added 1 changesets with 0 changes to 0 files