diff --git a/mercurial/templatefilters.py b/mercurial/templatefilters.py
--- a/mercurial/templatefilters.py
+++ b/mercurial/templatefilters.py
@@ -90,9 +90,8 @@ def age(date, abbrev=False):
 @templatefilter('basename')
 def basename(path):
     """Any text. Treats the text as a path, and returns the last
-    component of the path after splitting by the path separator
-    (ignoring trailing separators). For example, "foo/bar/baz" becomes
-    "baz" and "foo/bar//" becomes "bar".
+    component of the path after splitting by the path separator.
+    For example, "foo/bar/baz" becomes "baz" and "foo/bar//" becomes "".
     """
     return os.path.basename(path)
 
diff --git a/tests/test-command-template.t b/tests/test-command-template.t
--- a/tests/test-command-template.t
+++ b/tests/test-command-template.t
@@ -2218,6 +2218,11 @@ Age filter:
   $ cd ..
   $ rm -rf unstable-hash
 
+Filename filters:
+
+  $ hg debugtemplate '{"foo/bar"|basename}|{"foo/"|basename}|{"foo"|basename}|\n'
+  bar||foo|
+
 Add a dummy commit to make up for the instability of the above:
 
   $ echo a > a