parse_hwdb: bail with an error if no matches or groups are detected

pyparsing sometimes changes behaviour and stops giving matches. This should
allow us to detect such scenario. With this change, parse_hwdb fails with
pyparsing 2.4 on F31.

diff --git a/hwdb.d/parse_hwdb.py b/hwdb.d/parse_hwdb.py
index da0bca5..78c7f9b 100755 (executable)
--- a/hwdb.d/parse_hwdb.py
+++ b/hwdb.d/parse_hwdb.py
@@ -224,11 +224,13 @@ def check_properties(groups):
                 check_one_keycode(prop, parsed.VALUE)
 
 def print_summary(fname, groups):
+    n_matches = sum(len(matches) for matches, props in groups)
+    n_props = sum(len(props) for matches, props in groups)
     print('{}: {} match groups, {} matches, {} properties'
-          .format(fname,
-                  len(groups),
-                  sum(len(matches) for matches, props in groups),
-                  sum(len(props) for matches, props in groups)))
+          .format(fname, len(groups), n_matches, n_props))
+
+    if n_matches == 0 or n_props == 0:
+        error('{}: no matches or props'.format(fname))
 
 if __name__ == '__main__':
     args = sys.argv[1:] or glob.glob(os.path.dirname(sys.argv[0]) + '/[67]0-*.hwdb')