text ligatures off when character-spacing > 0

src/text/text_properties.cpp

@@ -98,6 +98,11 @@ void text_symbolizer_properties::process(text_layout & output, feature_impl cons
         format->fontset = format_defaults.fontset;
 
         format->font_feature_settings = util::apply_visitor(extract_value<font_feature_settings_ptr>(feature,attrs), format_defaults.font_feature_settings);
+        // Turn off ligatures if character_spacing > 0.
+        if (format->character_spacing > .0 && format->font_feature_settings->count() == 0)
+        {
+            format->font_feature_settings->append(font_feature_liga_off);
+        }
 
         tree_->apply(format, feature, attrs, output);
     }

tests/visual_tests/grids/text-font-features-500-500-1.0-grid-reference.json

@@ -35,9 +35,9 @@
   "                                                                                                                             ", 
   "                                                                                                                             ", 
   "                                                                                                                             ", 
-  "                                        !                          !       !!                                                ", 
-  "                                        !!   !!                !   !       !!    !  ! !  !                                   ", 
-  "                                   !!   !!   !!      !!!  !    !   !       !!   !!   !   !                                   ", 
+  "                                !!!                !               !       !                                                 ", 
+  "                                 !        !!       !           !   !       !      !    !!   !                                ", 
+  "                                 !   ! !  !!       !  !!  !    !   !       !  !!  !!   !!   !                                ", 
   "                                                                                                                             ", 
   "                                                                                                                             ", 
   "                                                                                                                             ",