From ae4ef72755d559c19665d1bb8325c42558bd4172 Mon Sep 17 00:00:00 2001
From: Craig Jennings <c@cjennings.net>
Date: Fri, 14 Nov 2025 12:40:38 -0600
Subject: apply undercurl patch for enhanced underline styles

Applied st-undercurl-0.9-20240103.diff cleanly with offset adjustments.

Benefits:
- Adds support for curly/wavy underlines (undercurl)
- Custom underline colors via SGR escape codes
- Compatible with Vim/NeoVim LSP diagnostics and spell-check
- Supports standard terminal features used by most modern terminals

Use cases:
- Editor spell-check with wavy underlines
- LSP warnings/errors with colored underlines
- Enhanced visual feedback in terminal applications
---
 st.h | 3 +++
 1 file changed, 3 insertions(+)

(limited to 'st.h')

diff --git a/st.h b/st.h
index 9cf12fd..497b3b5 100644
--- a/st.h
+++ b/st.h
@@ -38,6 +38,7 @@ enum glyph_attribute {
 	ATTR_SELECTED   = 1 << 12,
 	ATTR_BOXDRAW    = 1 << 13,
 	ATTR_BOLD_FAINT = ATTR_BOLD | ATTR_FAINT,
+	ATTR_DIRTYUNDERLINE = 1 << 15,
 };
 
 enum selection_mode {
@@ -69,6 +70,8 @@ typedef struct {
 	ushort mode;      /* attribute flags */
 	uint32_t fg;      /* foreground  */
 	uint32_t bg;      /* background  */
+	int ustyle;	  /* underline style */
+	int ucolor[3];    /* underline color */
 } Glyph;
 
 typedef Glyph *Line;
-- 
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