tahoe_cp: be consistent with "source.basename() is None" testing

diff --git a/src/allmydata/scripts/tahoe_cp.py b/src/allmydata/scripts/tahoe_cp.py
index 3089239275cc67899781d60afb1e27045183079c..46244e87ed2d5d5df038cecc9c8090e4b0096697 100644 (file)
--- a/src/allmydata/scripts/tahoe_cp.py
+++ b/src/allmydata/scripts/tahoe_cp.py
@@ -559,7 +559,7 @@ class Copier:
         _assert(isinstance(target, DirectoryTargets + MissingTargets), target)
 
         for source in sources:
-            if isinstance(source, FileSources) and not source.basename():
+            if isinstance(source, FileSources) and source.basename() is None:
                 self.to_stderr("when copying into a directory, all source files must have names, but %s is unnamed" % quote_output(source_specs[0]))
                 return 1
         return self.copy_things_to_directory(sources, target)