narrow: only send includepats and excludepats if they are not empty

If we send an empty includepats or excludepats argument to getbundle, it's
translated to `['']` on the server which causes problems because even though
it's empty, bool of that value if True and we end up creating differencematcher
with narrowspec.match() which results in unexpected behavior.

Differential Revision: https://phab.mercurial-scm.org/D5138

hgext/narrow/narrowcommands.py

@@ -141,8 +141,10 b' def pullbundle2extraprepare(orig, pullop'
     include, exclude = repo.narrowpats
     kwargs['oldincludepats'] = include
     kwargs['oldexcludepats'] = exclude
-    kwargs['includepats'] = include
-    kwargs['excludepats'] = exclude
+    if include:
+        kwargs['includepats'] = include
+    if exclude:
+        kwargs['excludepats'] = exclude
     # calculate known nodes only in ellipses cases because in non-ellipses cases
     # we have all the nodes
     if wireprototypes.ELLIPSESCAP in pullop.remote.capabilities():