From bbcdcd04a5f6c02c14d73d6bd0f53099b1fcb765 Mon Sep 17 00:00:00 2001
From: Michael Davis <mcarsondavis@gmail.com>
Date: Tue, 28 Mar 2023 22:51:11 -0500
Subject: [PATCH] tui: Handle keyboard enhancement check failure (#6438)

If the terminal doesn't send the primary device attributes response to
the query, the `terminal::supports_keyboard_enhancement` function from
crossterm may timeout and return an Err.

We should interpret this error to mean that the terminal doesn't support
the keyboard enhancement protocol rather than an error in claiming the
terminal.
---
 helix-tui/src/backend/crossterm.rs | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/helix-tui/src/backend/crossterm.rs b/helix-tui/src/backend/crossterm.rs
index 4b230f53..4d44f187 100644
--- a/helix-tui/src/backend/crossterm.rs
+++ b/helix-tui/src/backend/crossterm.rs
@@ -78,21 +78,20 @@ where
     }
 
     #[inline]
-    fn supports_keyboard_enhancement_protocol(&self) -> io::Result<bool> {
-        self.supports_keyboard_enhancement_protocol
-            .get_or_try_init(|| {
+    fn supports_keyboard_enhancement_protocol(&self) -> bool {
+        *self.supports_keyboard_enhancement_protocol
+            .get_or_init(|| {
                 use std::time::Instant;
 
                 let now = Instant::now();
-                let support = terminal::supports_keyboard_enhancement();
+                let supported = matches!(terminal::supports_keyboard_enhancement(), Ok(true));
                 log::debug!(
                     "The keyboard enhancement protocol is {}supported in this terminal (checked in {:?})",
-                    if matches!(support, Ok(true)) { "" } else { "not " },
+                    if supported { "" } else { "not " },
                     Instant::now().duration_since(now)
                 );
-                support
+                supported
             })
-            .copied()
     }
 }
 
@@ -125,7 +124,7 @@ where
         if config.enable_mouse_capture {
             execute!(self.buffer, EnableMouseCapture)?;
         }
-        if self.supports_keyboard_enhancement_protocol()? {
+        if self.supports_keyboard_enhancement_protocol() {
             execute!(
                 self.buffer,
                 PushKeyboardEnhancementFlags(
@@ -143,7 +142,7 @@ where
         if config.enable_mouse_capture {
             execute!(self.buffer, DisableMouseCapture)?;
         }
-        if self.supports_keyboard_enhancement_protocol()? {
+        if self.supports_keyboard_enhancement_protocol() {
             execute!(self.buffer, PopKeyboardEnhancementFlags)?;
         }
         execute!(