From 4b1ff3ed0fac24f5d9d4145f2ee8dd7927a61f94 Mon Sep 17 00:00:00 2001
From: Amr Gharbeia <amr@gharbeia.net>
Date: Thu, 14 May 2026 14:22:27 -0400
Subject: [PATCH] fix: move stty size to first priority in backend-size
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stty size via subprocess is the most reliable method — it
returns the correct 59x83 from the user's terminal. Move it
before ioctl to ensure it's tried first.
---
 src/backend/modern.lisp | 30 +++++++++++++++---------------
 src/backend/simple.lisp | 14 +++++++++++++-
 2 files changed, 28 insertions(+), 16 deletions(-)

diff --git a/src/backend/modern.lisp b/src/backend/modern.lisp
index a87fd30..a9a4e8f 100644
--- a/src/backend/modern.lisp
+++ b/src/backend/modern.lisp
@@ -162,21 +162,9 @@ as a fallback when a keyword is not in *named-colors*.")
   (values))
 
 (defmethod backend-size ((b modern-backend))
-  (or (ignore-errors
-        (let* ((+tiocgwinsz+ 21523)  ; 0x5413 on Linux
-               (winsize (sb-alien:make-alien sb-alien:unsigned-short 4)))
-          (unwind-protect
-               (progn
-                 (sb-unix:unix-ioctl (sb-sys:fd-stream-fd (backend-output-stream b))
-                                     +tiocgwinsz+
-                                     (sb-alien:alien-sap winsize))
-                 (values (sb-alien:deref winsize 1)  ;; cols
-                         (sb-alien:deref winsize 0))) ;; rows
-            (sb-alien:free-alien winsize))))
-      ;; stty size via subprocess — reliable on every Unix, bypasses
-      ;; SBCL's alien/ioctl quirks. Returns "ROWS COLS".  Use sh -c
-      ;; with explicit /dev/tty to ensure stty sees the real terminal
-      ;; (uiop:run-program may redirect stdin).
+  (or ;; stty size via subprocess — most reliable across all systems.
+      ;; Returns "ROWS COLS". Uses explicit /dev/tty to bypass any
+      ;; stdin redirection from uiop:run-program.
       (ignore-errors
         (let* ((out (uiop:run-program '("sh" "-c" "stty size < /dev/tty")
                                       :output :string
@@ -188,6 +176,18 @@ as a fallback when a keyword is not in *named-colors*.")
                   (cols (parse-integer (second parts) :junk-allowed t)))
               (when (and rows cols (> rows 0) (> cols 0))
                 (values cols rows))))))
+      ;; ioctl on stdout fd — fast, correct after SIGWINCH at runtime.
+      (ignore-errors
+        (let* ((+tiocgwinsz+ 21523)  ; 0x5413 on Linux
+               (winsize (sb-alien:make-alien sb-alien:unsigned-short 4)))
+          (unwind-protect
+               (progn
+                 (sb-unix:unix-ioctl (sb-sys:fd-stream-fd (backend-output-stream b))
+                                     +tiocgwinsz+
+                                     (sb-alien:alien-sap winsize))
+                 (values (sb-alien:deref winsize 1)  ;; cols
+                         (sb-alien:deref winsize 0))) ;; rows
+            (sb-alien:free-alien winsize))))
       ;; Direct ioctl on /dev/tty — opens the real controlling terminal.
       (ignore-errors
         (let ((tty-fd (sb-unix:unix-open "/dev/tty" 0 0)))  ; O_RDONLY
diff --git a/src/backend/simple.lisp b/src/backend/simple.lisp
index 52bdce1..bab5a3b 100644
--- a/src/backend/simple.lisp
+++ b/src/backend/simple.lisp
@@ -22,7 +22,19 @@
   (values))
 
 (defmethod backend-size ((b simple-backend))
-  (or (ignore-errors
+  (or ;; stty size via subprocess — most reliable across all systems.
+      (ignore-errors
+        (let* ((out (uiop:run-program '("sh" "-c" "stty size < /dev/tty")
+                                      :output :string
+                                      :ignore-error-status t))
+               (parts (and out (uiop:split-string
+                                 (string-trim '(#\newline #\space) out)))))
+          (when (and parts (= (length parts) 2))
+            (let ((rows (parse-integer (first parts) :junk-allowed t))
+                  (cols (parse-integer (second parts) :junk-allowed t)))
+              (when (and rows cols (> rows 0) (> cols 0))
+                (values cols rows))))))
+      (ignore-errors
         (let* ((+tiocgwinsz+ 21523)
                (winsize (sb-alien:make-alien sb-alien:unsigned-short 4)))
           (unwind-protect