Fix: Monospaced fonts wrong width

[why]
With commit
  821ac68  Create symbols only font directly from sfd template

we have a default width for source fonts without a width (i.e. empty
fonts).

Unfortunately the detection for 'empty font' is wrong.

[how]
Reorder the commands such that we have a meaningful calculation.

Maybe this has been broken by too many (manual) rebases.

Fixes: ryanoasis#895

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

Author: Finii

font-patcher

@@ -835,7 +835,7 @@ class font_patcher:
         # Ignore the y-values, os2_winXXXXX values set above are used for line height
         #
         # 0x00-0x17f is the Latin Extended-A range
-        for glyph in range(0x00, 0x17f):
+        for glyph in range(0x21, 0x17f):
             if glyph in range(0x7F, 0xBF):
                 continue # ignore special characters like '1/4' etc
             try:
@@ -848,6 +848,7 @@ class font_patcher:
                 self.font_dim['xmax'] = xmax
 
         # Calculate font height
+        self.font_dim['height'] = abs(self.font_dim['ymin']) + self.font_dim['ymax']
         if self.font_dim['height'] == 0:
             # This can only happen if the input font is empty
             # Assume we are using our prepared templates
@@ -857,9 +858,8 @@ class font_patcher:
                 'xmax'  : self.sourceFont.em,
                 'ymax'  : self.sourceFont.ascent,
                 'width' : self.sourceFont.em,
-                'height': 0,
+                'height': abs(self.sourceFont.descent) + self.sourceFont.ascent,
             }
-        self.font_dim['height'] = abs(self.font_dim['ymin']) + self.font_dim['ymax']
 
 
     def get_scale_factor(self, sym_dim):