fix(highlight): apply 'winblend' to float border (#25981)

2 files changed, 10 insertions, 5 deletions

diff --git a/src/nvim/highlight.c b/src/nvim/highlight.c
index 88bf5dbd6e..a0114bbbe8 100644
--- a/src/nvim/highlight.c
+++ b/src/nvim/highlight.c
@@ -374,10 +374,15 @@ void update_window_hl(win_T *wp, bool invalid)
       if (wp->w_float_config.border_hl_ids[i]) {
         attr = hl_get_ui_attr(ns_id, HLF_BORDER,
                               wp->w_float_config.border_hl_ids[i], false);
-        HlAttrs a = syn_attr2entry(attr);
-        if (a.hl_blend) {
-          wp->w_float_config.shadow = true;
-        }
+      }
+      HlAttrs a = syn_attr2entry(attr);
+      if (a.hl_blend == -1 && wp->w_p_winbl > 0) {
+        HlEntry entry = attr_entry(attr);
+        a.hl_blend = entry.attr.hl_blend = (int)wp->w_p_winbl;
+        attr = get_attr_entry(entry);
+      }
+      if (a.hl_blend > 0) {
+        wp->w_float_config.shadow = true;
       }
       wp->w_float_config.border_attr[i] = attr;
     }
diff --git a/src/nvim/option.c b/src/nvim/option.c
index 7005b63cac..690a03f1a0 100644
--- a/src/nvim/option.c
+++ b/src/nvim/option.c
@@ -2686,7 +2686,7 @@ static const char *did_set_winblend(optset_T *args)
   if (value != old_value) {
     win->w_p_winbl = MAX(MIN(win->w_p_winbl, 100), 0);
     win->w_hl_needs_update = true;
-    check_blending(curwin);
+    check_blending(win);
   }
 
   return NULL;