match: use ctx.getfileset() instead of fileset.getfileset()

Resolves an import cycle involving match and merge.

mercurial/match.py

@@ -6,7 +6,7 b''
 # GNU General Public License version 2 or any later version.
 
 import re
-import util, fileset, pathutil
+import util, pathutil
 from i18n import _
 
 def _rematcher(pat):
@@ -26,7 +26,7 b' def _expandsets(pats, ctx):'
         if kind == 'set':
             if not ctx:
                 raise util.Abort("fileset expression with no context")
-            s = fileset.getfileset(ctx, expr)
+            s = ctx.getfileset(expr)
             fset.update(s)
             continue
         other.append((kind, expr))

tests/test-module-imports.t

@@ -39,6 +39,4 b' these may expose other cycles.'
      stdlib:    formatter
      relative:  config, error, scmutil, util
   Import cycle: mercurial.repoview -> mercurial.revset -> mercurial.repoview
-  Import cycle: mercurial.fileset -> mercurial.merge -> mercurial.subrepo -> mercurial.match -> mercurial.fileset
   Import cycle: mercurial.cmdutil -> mercurial.context -> mercurial.subrepo -> mercurial.cmdutil -> mercurial.cmdutil
-  Import cycle: mercurial.filemerge -> mercurial.match -> mercurial.fileset -> mercurial.merge -> mercurial.filemerge