#15509: If %action substitution produces a null string, drop it.
Patch by Anton Barkovsky, comment addition by me.
This showed up as a bug in 3.3 because the definition for Chrome
produced such an empty string. This fix is tested in 3.3+;
backporting the new test suite is more trouble than it is worth.
diff --git a/Misc/NEWS b/Misc/NEWS
index 544bf67..93b679b 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -115,6 +115,9 @@
Library
-------
+- Issue #15509: webbrowser.UnixBrowser no longer passes empty arguments to
+ Popen when %action substitutions produce empty strings.
+
- Issue #12776,#11839: call argparse type function (specified by add_argument)
only once. Before, the type function was called twice in the case where the
default was specified and the argument was given as well. This was