[shaping] use constructor in test, now mandatory since cmap is cached

Author: benoitkugler

font/font.go

@@ -610,6 +610,8 @@ func loadGDEF(ld *ot.Loader, axisCount int, gsub, gpos []byte) (tables.GDEF, err
 // Face is a font with user-provided settings.
 // Contrary to the [*Font] objects, Faces are NOT safe for concurrent use.
 // A Face caches glyph extents and rune to glyph mapping, and should be reused when possible.
+//
+// Also note that an empty [Face] is invalid : the [NewFace] constructor is required to properly init caches.
 type Face struct {
 	*Font
 

shaping/input_test.go

@@ -69,9 +69,9 @@ func TestSplitByFontGlyphs(t *testing.T) {
 		availableFaces []*font.Face
 	}
 
-	universalFont := &font.Face{Font: &font.Font{Cmap: universalCmap{}}}
-	lowerFont := &font.Face{Font: &font.Font{Cmap: lowerCmap{}}}
-	upperFont := &font.Face{Font: &font.Font{Cmap: upperCmap{}}}
+	universalFont := font.NewFace(&font.Font{Cmap: universalCmap{}})
+	lowerFont := font.NewFace(&font.Font{Cmap: lowerCmap{}})
+	upperFont := font.NewFace(&font.Font{Cmap: upperCmap{}})
 
 	latinFont := loadOpentypeFont(t, "../font/testdata/Roboto-Regular.ttf")
 	arabicFont := loadOpentypeFont(t, "../font/testdata/Amiri-Regular.ttf")