From 66950a4a537d1c21fe63a7c53d3c254bbe83679a Mon Sep 17 00:00:00 2001
From: Riccardo Mazzarini <me@noib3.dev>
Date: Tue, 2 Jun 2026 18:03:45 +0200
Subject: [PATCH] libghostty: add option to set default cursor blink

Adds an option to `libghostty-vt` to configure whether the default
cursor displayed when an app sends a DECSCUSR reset sequence should
blink.
---
 include/ghostty/vt/terminal.h    | 10 ++++++++++
 src/terminal/c/terminal.zig      |  9 +++++++++
 src/terminal/stream_terminal.zig |  5 ++++-
 3 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/include/ghostty/vt/terminal.h b/include/ghostty/vt/terminal.h
index 9ddc2b54b..9b573c36a 100644
--- a/include/ghostty/vt/terminal.h
+++ b/include/ghostty/vt/terminal.h
@@ -637,6 +637,16 @@ typedef enum GHOSTTY_ENUM_TYPED {
    * Input type: GhosttyTerminalCursorStyle*
    */
   GHOSTTY_TERMINAL_OPT_DEFAULT_CURSOR_STYLE = 22,
+
+  /**
+   * Set whether the default cursor should blink when reset by DECSCUSR
+   * (CSI 0 q).
+   *
+   * A NULL value pointer resets to the built-in default of not blinking.
+   *
+   * Input type: bool*
+   */
+  GHOSTTY_TERMINAL_OPT_DEFAULT_CURSOR_BLINK = 23,
   GHOSTTY_TERMINAL_OPT_MAX_VALUE = GHOSTTY_ENUM_MAX_VALUE,
 } GhosttyTerminalOption;
 
diff --git a/src/terminal/c/terminal.zig b/src/terminal/c/terminal.zig
index 59fac7e70..6d5ca4c5c 100644
--- a/src/terminal/c/terminal.zig
+++ b/src/terminal/c/terminal.zig
@@ -328,6 +328,7 @@ pub const Option = enum(c_int) {
     apc_max_bytes_kitty = 20,
     selection = 21,
     default_cursor_style = 22,
+    default_cursor_blink = 23,
 
     /// Input type expected for setting the option.
     pub fn InType(comptime self: Option) type {
@@ -352,6 +353,7 @@ pub const Option = enum(c_int) {
             .apc_max_bytes, .apc_max_bytes_kitty => ?*const usize,
             .selection => ?*const selection_c.CSelection,
             .default_cursor_style => ?*const TerminalCursorStyle,
+            .default_cursor_blink => ?*const bool,
         };
     }
 };
@@ -474,6 +476,13 @@ fn setTyped(
                 wrapper.terminal.screens.active.cursor.cursor_style = style;
             }
         },
+        .default_cursor_blink => {
+            const blink = if (value) |ptr| ptr.* else false;
+            wrapper.stream.handler.default_cursor_blink = blink;
+            if (wrapper.stream.handler.default_cursor) {
+                wrapper.terminal.modes.set(.cursor_blinking, blink);
+            }
+        },
     }
     return .success;
 }
diff --git a/src/terminal/stream_terminal.zig b/src/terminal/stream_terminal.zig
index 560e12c2a..113521072 100644
--- a/src/terminal/stream_terminal.zig
+++ b/src/terminal/stream_terminal.zig
@@ -46,6 +46,7 @@ pub const Handler = struct {
     /// Default cursor style used by DECSCUSR reset (CSI 0 q).
     default_cursor: bool = true,
     default_cursor_style: Screen.CursorStyle = .block,
+    default_cursor_blink: bool = false,
 
     pub const Effects = struct {
         /// Called when the terminal needs to write data back to the pty,
@@ -159,7 +160,8 @@ pub const Handler = struct {
                 self.default_cursor = false;
 
                 const blink = switch (value) {
-                    .default, .steady_block, .steady_bar, .steady_underline => false,
+                    .default => self.default_cursor_blink,
+                    .steady_block, .steady_bar, .steady_underline => false,
                     .blinking_block, .blinking_bar, .blinking_underline => true,
                 };
                 const style: Screen.CursorStyle = switch (value) {
@@ -241,6 +243,7 @@ pub const Handler = struct {
             .full_reset => {
                 self.terminal.fullReset();
                 self.default_cursor = true;
+                self.terminal.modes.set(.cursor_blinking, self.default_cursor_blink);
                 self.terminal.screens.active.cursor.cursor_style = self.default_cursor_style;
             },
             .start_hyperlink => try self.terminal.screens.active.startHyperlink(value.uri, value.id),