From 4a384aa27275db509b4395ccb5cd6398fb0011f4 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Sun, 13 Aug 2023 15:12:13 -0700
Subject: [PATCH] parse and respect mode 1036

---
 src/Surface.zig           | 22 +++++++++++++++++++---
 src/apprt/glfw.zig        |  9 +++------
 src/terminal/Terminal.zig |  1 +
 src/terminal/ansi.zig     |  3 +++
 src/termio/Exec.zig       |  2 +-
 5 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/src/Surface.zig b/src/Surface.zig
index 0d08901d7..3462df8f0 100644
--- a/src/Surface.zig
+++ b/src/Surface.zig
@@ -1006,7 +1006,9 @@ pub fn charCallback(
     }
 
     // Critical area
-    {
+    const critical: struct {
+        alt_esc_prefix: bool,
+    } = critical: {
         self.renderer_state.mutex.lock();
         defer self.renderer_state.mutex.unlock();
 
@@ -1019,17 +1021,31 @@ pub fn charCallback(
         // We want to scroll to the bottom
         // TODO: detect if we're at the bottom to avoid the render call here.
         try self.io.terminal.scrollViewport(.{ .bottom = {} });
-    }
+
+        break :critical .{
+            .alt_esc_prefix = self.io.terminal.modes.alt_esc_prefix,
+        };
+    };
 
     var data: termio.Message.WriteReq.Small.Array = undefined;
 
     // Prefix our data with ESC if we have alt pressed.
     var i: u8 = 0;
     if (mods.alt) alt: {
+        // If the terminal explicitly disabled this feature using mode 1036,
+        // then we don't send the prefix.
+        if (!critical.alt_esc_prefix) {
+            log.debug("alt_esc_prefix disabled with mode, not sending esc prefix", .{});
+            break :alt;
+        }
+
         // On macOS, we have to opt-in to using alt because option
         // by default is a unicode character sequence.
         if (comptime builtin.target.isDarwin()) {
-            if (!self.config.macos_option_as_alt) break :alt;
+            if (!self.config.macos_option_as_alt) {
+                log.debug("macos_option_as_alt disabled, not sending esc prefix", .{});
+                break :alt;
+            }
         }
 
         data[i] = 0x1b;
diff --git a/src/apprt/glfw.zig b/src/apprt/glfw.zig
index 44467cb9b..195f67646 100644
--- a/src/apprt/glfw.zig
+++ b/src/apprt/glfw.zig
@@ -611,16 +611,12 @@ pub const Surface = struct {
         glfw_action: glfw.Action,
         glfw_mods: glfw.Mods,
     ) void {
+        const tracy = trace(@src());
+        defer tracy.end();
         _ = scancode;
 
         const core_win = window.getUserPointer(CoreSurface) orelse return;
 
-        // Reset our consumption state
-        core_win.rt_surface.key_consumed = false;
-
-        const tracy = trace(@src());
-        defer tracy.end();
-
         // Convert our glfw types into our input types
         const mods: input.Mods = @bitCast(glfw_mods);
         const action: input.Action = switch (glfw_action) {
@@ -756,6 +752,7 @@ pub const Surface = struct {
 
         // TODO: we need to do mapped keybindings
 
+        core_win.rt_surface.key_mods = mods;
         core_win.rt_surface.key_consumed = core_win.keyCallback(
             action,
             key,
diff --git a/src/terminal/Terminal.zig b/src/terminal/Terminal.zig
index 7972d696b..ff9b0c8f3 100644
--- a/src/terminal/Terminal.zig
+++ b/src/terminal/Terminal.zig
@@ -91,6 +91,7 @@ modes: packed struct {
     deccolm: bool = false, // 3,
     deccolm_supported: bool = false, // 40
     keypad_keys: bool = false, // 66
+    alt_esc_prefix: bool = true, // 1036
 
     focus_event: bool = false, // 1004
     mouse_alternate_scroll: bool = true, // 1007
diff --git a/src/terminal/ansi.zig b/src/terminal/ansi.zig
index 2429210e0..377007bda 100644
--- a/src/terminal/ansi.zig
+++ b/src/terminal/ansi.zig
@@ -121,6 +121,9 @@ pub const Mode = enum(u16) {
     /// Report mouse position in the SGR format as pixels, instead of cells.
     mouse_format_sgr_pixels = 1016,
 
+    /// The alt key sends esc as a prefix before any character. On by default.
+    alt_esc_prefix = 1036,
+
     /// Alternate screen mode with save cursor and clear on enter.
     alt_screen_save_cursor_clear_enter = 1049,
 
diff --git a/src/termio/Exec.zig b/src/termio/Exec.zig
index 8f7d05568..1aec3f269 100644
--- a/src/termio/Exec.zig
+++ b/src/termio/Exec.zig
@@ -1274,8 +1274,8 @@ const StreamHandler = struct {
             .mouse_format_sgr_pixels => self.terminal.modes.mouse_format = if (enabled) .sgr_pixels else .x10,
 
             .mouse_alternate_scroll => self.terminal.modes.mouse_alternate_scroll = enabled,
-
             .focus_event => self.terminal.modes.focus_event = enabled,
+            .alt_esc_prefix => self.terminal.modes.alt_esc_prefix = enabled,
 
             else => if (enabled) log.warn("unimplemented mode: {}", .{mode}),
         }