Use selection foreground color for underlines as well

Fixes #1982

docs/changelog.rst

@@ -25,6 +25,7 @@ To update |kitty|, :doc:`follow the instructions <binary>`.
 - Linux: Allow using fonts with spacing=90 in addition to fonts with
   spacing=100 (:iss:`1968`)
 
+- Use selection foreground color for underlines as well (:iss:`1982`)
 
 0.14.4 [2019-08-31]
 ---------------------

kitty/cell_vertex.glsl

@@ -172,13 +172,15 @@ void main() {
     foreground = color_to_vec(resolved_fg);
     float has_dim = float((text_attrs >> DIM_SHIFT) & ONE);
     effective_text_alpha = inactive_text_alpha * mix(1.0, dim_opacity, has_dim);
-#ifdef USE_SELECTION_FG
-    // Selection
-    foreground = choose_color(float(is_selected & ONE), color_to_vec(highlight_fg), foreground);
-#endif
-    // Underline and strike through (rendered via sprites)
     float in_url = float((is_selected & TWO) >> 1);
     decoration_fg = choose_color(in_url, color_to_vec(url_color), to_color(colors[2], resolved_fg));
+#ifdef USE_SELECTION_FG
+    // Selection
+    vec3 selection_color = color_to_vec(highlight_fg);
+    foreground = choose_color(float(is_selected & ONE), selection_color, foreground);
+    decoration_fg = choose_color(float(is_selected & ONE), selection_color, decoration_fg);
+#endif
+    // Underline and strike through (rendered via sprites)
     underline_pos = choose_color(in_url, to_sprite_pos(pos, url_style, ZERO, ZERO), to_sprite_pos(pos, (text_attrs >> DECORATION_SHIFT) & THREE, ZERO, ZERO));
     strike_pos = to_sprite_pos(pos, ((text_attrs >> STRIKE_SHIFT) & ONE) * FOUR, ZERO, ZERO);