pythondistdeps.py: When parsing extras name, take the rightmost +

python-rpm-generators.spec

@@ -1,7 +1,7 @@
 Name:           python-rpm-generators
 Summary:        Dependency generators for Python RPMs
 Version:        11
-Release:        9%{?dist}
+Release:        10%{?dist}
 
 # Originally all those files were part of RPM, so license is kept here
 License:        GPLv2+
@@ -47,6 +47,9 @@ install -Dpm0755 -t %{buildroot}%{_rpmconfigdir} *.py
 %{_rpmconfigdir}/pythonbundles.py
 
 %changelog
+* Tue Jul 21 2020 Miro Hrončok <mhroncok@redhat.com> - 11-10
+- pythondistdeps: Split Python Extras names after the rightmost plus sign
+
 * Fri Jul 10 2020 Tomas Orsava <torsava@redhat.com> - 11-9
 - pythondistdeps: Implement provides/requires for extras packages
 - Enable --require-extras-subpackages

pythondistdeps.py

@@ -205,8 +205,15 @@ if __name__ == "__main__":
 
     # Is this script being run for an extras subpackage?
     extras_subpackage = None
-    if args.package_name:
-        package_name_parts = args.package_name.partition('+')
+    if args.package_name and '+' in args.package_name:
+        # The extras names are encoded in the package names after the + sign.
+        # We take the part after the rightmost +, ignoring when empty,
+        # this allows packages like nicotine+ or c++ to work fine.
+        # While packages with names like +spam or foo+bar would break,
+        # names started with the plus sign are not very common
+        # and pluses in the middle can be easily replaced with dashes.
+        # Python extras names don't contain pluses according to PEP 508.
+        package_name_parts = args.package_name.rpartition('+')
         extras_subpackage = package_name_parts[2] or None
 
     for f in (args.files or stdin.readlines()):