Add edge case for Cb0

Cb0 is an invalid MIDI note and should have a sentinel value of 255u.

cases.txt

@@ -34,3 +34,4 @@ C19 228
 C20 240
 C21 252
 D#21 255
+Cb0 255

midi-utils.c

@@ -87,5 +87,9 @@ unsigned char MIDI_GetNoteFromName(const char* name) {
 		return 255u;
 	}
 
+	if (octave == 0 && octave_offset < 0) {
+		return 255u;
+	}
+
 	return ((octave * 12) + octave_offset) + pitch_class;
 }

test-note-names.c

@@ -13,12 +13,19 @@ int main(void) {
 		fscanf(f, "%s %d\n", read_note_name, &read_note_value);
 		unsigned int actual_note_value = MIDI_GetNoteFromName(read_note_name);
 		printf("MIDI_GetNoteFromName(\"%s\")...", read_note_name);
+		printf("(%d == %d) ", read_note_value, actual_note_value);
 		assert(read_note_value == actual_note_value);
 		printf("OK!\n");
 
-		printf("MIDI_GetNoteName(%d)...", read_note_value);
-		assert(!strcmp(MIDI_GetNoteName(read_note_value), read_note_name));
-		printf("OK!\n");
+		if (read_note_value != 255u || !strcmp(read_note_name, "D#21")) {
+			printf("MIDI_GetNoteName(%d)...", read_note_value);
+			char* actual_note_name = MIDI_GetNoteName(read_note_value);
+
+			printf("(%s == %s) ", read_note_name, actual_note_name);
+			assert(!strcmp(read_note_name, actual_note_name));
+
+			printf("OK!\n");
+		}
 	}
 
 	fclose(f);