# HG changeset patch
# User Augie Fackler <augie@google.com>
# Date 1519225802 18000
# Node ID f62369667a7cbe3b1e7ee1fb4f95e4ca880c15f1
# Parent  f85e32a5e5c869c248167a72518a6cc3d856b002
py3: use list comprehensions instead of filter where we need to eagerly filter

These two uses of filter() are then checked for truthiness, but on Python 3:

>>> bool(filter(None, []))
True

So we need to stop depending on that. Fortunately it's easy to replace
the filter with an equivalent list comprehension.

Differential Revision: https://phab.mercurial-scm.org/D2364

diff -r f85e32a5e5c8 -r f62369667a7c mercurial/cmdutil.py
--- a/mercurial/cmdutil.py	Wed Feb 21 10:08:35 2018 -0500
+++ b/mercurial/cmdutil.py	Wed Feb 21 10:10:02 2018 -0500
@@ -1831,7 +1831,7 @@
                 else:
                     self.revs.discard(value)
                     ctx = change(value)
-                    matches = filter(match, ctx.files())
+                    matches = [f for f in ctx.files() if match(f)]
                     if matches:
                         fncache[value] = matches
                         self.set.add(value)
diff -r f85e32a5e5c8 -r f62369667a7c mercurial/copies.py
--- a/mercurial/copies.py	Wed Feb 21 10:08:35 2018 -0500
+++ b/mercurial/copies.py	Wed Feb 21 10:10:02 2018 -0500
@@ -685,8 +685,8 @@
     # the base and present in the source.
     # Presence in the base is important to exclude added files, presence in the
     # source is important to exclude removed files.
-    missingfiles = filter(lambda f: f not in m1 and f in base and f in c2,
-                          changedfiles)
+    filt = lambda f: f not in m1 and f in base and f in c2
+    missingfiles = [f for f in changedfiles if filt(f)]
 
     if missingfiles:
         basenametofilename = collections.defaultdict(list)