merge: remove unnecessary matcher checks

As part of changing manifest.diff to accept a matcher, a previous patch added
matcher calls to each location in merge.manifestmerge that tested if 'x in mf'
to maintain the same behavior as before. After analyzing it further, this
matcher call isn't needed, and in fact hurts future patches ability to use the
matcher here.

Basically, all these 'if x in mf' checks were checking if a matched file's copy
source was in the matcher as well. This meant if you passed a matcher for just
file foo, it would not return file bar even if foo was a copy of bar. Since
manifestmerge cares about copy information, let's allow all lookups of copy
sources.

We also update one spot with a 'is not None' check, since it wasn't obvious that
the value could sometimes be None before, which broke when we called
matcher(None).

A future patch adds matcher optimizations to manifestmerge which causes this
code path to get covered by existing tests.

mercurial/merge.py

@@ -858,7 +858,7 b' def manifestmerge(repo, wctx, p2, pa, br'
                 pass # we'll deal with it on m2 side
             elif f in movewithdir: # directory rename, move local
                 f2 = movewithdir[f]
-                if matcher(f2) and f2 in m2:
+                if f2 in m2:
                     actions[f2] = ('m', (f, f2, None, True, pa.node()),
                                    "remote directory rename, both created")
                 else:
@@ -887,7 +887,7 b' def manifestmerge(repo, wctx, p2, pa, br'
                 pass # we'll deal with it on m1 side
             elif f in movewithdir:
                 f2 = movewithdir[f]
-                if matcher(f2) and f2 in m1:
+                if f2 in m1:
                     actions[f2] = ('m', (f2, f, None, False, pa.node()),
                                    "local directory rename, both created")
                 else:
@@ -895,7 +895,7 b' def manifestmerge(repo, wctx, p2, pa, br'
                                    "local directory rename - get from " + f)
             elif f in copy:
                 f2 = copy[f]
-                if matcher(f2) and f2 in m2:
+                if f2 in m2:
                     actions[f] = ('m', (f2, f, f2, False, pa.node()),
                                   "remote copied from " + f2)
                 else:
@@ -927,7 +927,7 b' def manifestmerge(repo, wctx, p2, pa, br'
                         # new file added in a directory that was moved
                         df = dirmove[d] + f[len(d):]
                         break
-                if matcher(df) and df in m1:
+                if df is not None and df in m1:
                     actions[df] = ('m', (df, f, f, False, pa.node()),
                             "local directory rename - respect move from " + f)
                 elif acceptremote: