[ABCFontFace.get_missing_glyphs] Don't try to convert 0xF020-0xF0FF char to the cmap encoding

Author: moi15moi

font_collector/font/abc_font_face.py

@@ -307,8 +307,10 @@ def get_missing_glyphs(
                 if cmap_encoding == "unicode":
                     codepoint = ord(char)
                 else:
+                    symbol_cmap = False
                     if cmap_encoding == "unknown":
                         if platform_id == 3 and encoding_id == 0:
+                            symbol_cmap = True
                             if support_only_ascii_char_for_symbol_font and not char.isascii():
                                 continue
                             cmap_encoding = FontParser.get_symbol_cmap_encoding(face)
@@ -320,10 +322,15 @@ def get_missing_glyphs(
                             # cmap not supported
                             continue
 
-                    try:
-                        codepoint = int.from_bytes(char.encode(cmap_encoding), "big")
-                    except UnicodeEncodeError:
-                        continue
+                    if symbol_cmap and (0xF020 <= ord(char) and ord(char) <= 0xF0FF):
+                        # If the character is already a "symbol" character (a.k.a is between 0xF020 and 0xF0FF),
+                        # GDI directly use it's codepoint.
+                        codepoint = ord(char)
+                    else:
+                        try:
+                            codepoint = int.from_bytes(char.encode(cmap_encoding), "big")
+                        except UnicodeEncodeError:
+                            continue
 
                 # GDI/Libass modify the codepoint for microsoft symbol cmap.
                 # See: https://github.com/libass/libass/blob/04a208d5d200360d2ac75f8f6cfc43dd58dd9225/libass/ass_font.c#L249-L250

tests/font/test_normal_font_face.py

@@ -137,6 +137,13 @@ def test_font_get_missing_glyphs_cmap_encoding_0():
     missing_glyphs = font_face.get_missing_glyphs("Έκθεση για Απασχόληση Dream Top Co. Οι επιλογές À a", True)
     assert missing_glyphs == set("ΈκθεσηγιαπασχόλησηΟιεπιλογέςÀΑ")
 
+    # 0xF152 > 0xF0FF and there is a entry of this character in the cmap. We must ignore it.
+    missing_glyphs = font_face.get_missing_glyphs(chr(0xF152))
+    assert missing_glyphs == set(chr(0xF152))
+
+    # GDI support to directly have the character with the 0xF000 flag
+    missing_glyphs = font_face.get_missing_glyphs(chr(0xF0FF))
+    assert missing_glyphs == set()
 
 def test_font_get_missing_glyphs_cmap_encoding_1():
     font_cmap_encoding_1 = Path(os.path.join(os.path.dirname(dir_path), "file", "fonts", "font_cmap_encoding_1.ttf"))