patch 8.2.0906: when setting 'termguicolors' SpellBad is no longer red
Problem: When setting 'termguicolors' SpellBad is no longer red.
Solution: Only use the RGB guisp color for cterm when using the "underline"
or "undercurl" attributes to avoid the background color to be
cleared. Also make t_8u empty when the termresponse indicates a
real xterm. (closes #6207)
diff --git a/src/highlight.c b/src/highlight.c
index 9ce6102..6291f24 100644
--- a/src/highlight.c
+++ b/src/highlight.c
@@ -2929,7 +2929,12 @@
# endif
at_en.ae_u.cterm.fg_rgb = GUI_MCH_GET_RGB2(sgp->sg_gui_fg);
at_en.ae_u.cterm.bg_rgb = GUI_MCH_GET_RGB2(sgp->sg_gui_bg);
- at_en.ae_u.cterm.ul_rgb = GUI_MCH_GET_RGB2(sgp->sg_gui_sp);
+ // Only use the underline/undercurl color when used, it may clear the
+ // background color if not supported.
+ if (sgp->sg_cterm & (HL_UNDERLINE | HL_UNDERCURL))
+ at_en.ae_u.cterm.ul_rgb = GUI_MCH_GET_RGB2(sgp->sg_gui_sp);
+ else
+ at_en.ae_u.cterm.ul_rgb = INVALCOLOR;
if (at_en.ae_u.cterm.fg_rgb == INVALCOLOR
&& at_en.ae_u.cterm.bg_rgb == INVALCOLOR)
{