font-patcher: Improve weight checking

[why]
When the font does not have a PSweight string the font-patcher bugs.

[how]
Rewrite the code to be more robust against unexpected weight values.
Also make detected problems non-fatal.

Reported-by: František Hanzlík <[email protected]>
Signed-off-by: Fini Jastrow <[email protected]>

bin/scripts/name_parser/FontnameParser.py

@@ -283,10 +283,14 @@ def check_weights(self, font):
         os2_weight = font.os2_weight
         ps_weight = FontnameTools.weight_string_to_number(font.weight)
         name_weight = FontnameTools.weight_string_to_number(weight)
+        weightproblem = False
+        if ps_weight is None:
+            self.logger.warn('Can not parse PS-weight: {}'.format(restored_weight_token))
+            weightproblem = True
         if name_weight is None:
-            self.logger.error('Can not parse name for weight: {}'.format(restored_weight_token))
-            return
-        if abs(os2_weight - ps_weight) > 50 or abs(os2_weight - name_weight) > 50:
+            self.logger.warn('Can not parse name for weight: {}'.format(restored_weight_token))
+            weightproblem = True
+        if weightproblem or abs(os2_weight - ps_weight) > 50 or abs(os2_weight - name_weight) > 50:
             self.logger.warning('Possible problem with the weight metadata detected, check with --debug')
         self.logger.debug('Weight approximations: OS2/PS/Name: {}/{}/{} (from {}/\'{}\'/\'{}\')'.format(
             os2_weight, ps_weight, name_weight,

bin/scripts/name_parser/FontnameTools.py

@@ -287,7 +287,7 @@ def postscript_char_filter(name):
     @staticmethod
     def weight_string_to_number(w):
         """ Convert a common string approximation to a PS/2 weight value """
-        if not len(w):
+        if not isinstance(w, str) or len(w) < 1:
             return 400
         for num, strs in FontnameTools.equivalent_weights.items():
             if w.lower() in strs:

font-patcher

@@ -6,7 +6,7 @@
 from __future__ import absolute_import, print_function, unicode_literals
 
 # Change the script version when you edit this script:
-script_version = "4.5.2"
+script_version = "4.5.3"
 
 version = "3.0.2"
 projectName = "Nerd Fonts"