Set the current buffer before handling key events

There's no guarantee that the global current buffer matches the selected
window's buffer. For example, the following  will output "*Messages*" regardless
of the actual current buffer:

  (progn
    (run-at "1 sec" nil (lambda ()
                          (with-current-buffer (get-buffer "*Messages*")
                            (sit-for 5))))
    (run-at "2 sec" nil (lambda () (message (buffer-name)))))

* exwm-input.el (exwm-input--on-KeyPress): Set the current buffer to selected
window's current buffer.

1 files changed, 13 insertions, 12 deletions

diff --git a/exwm-input.el b/exwm-input.el
index 2d3b48189826..8cd54c69b848 100644
--- a/exwm-input.el
+++ b/exwm-input.el
@@ -441,18 +441,19 @@ ARGS are additional arguments to CALLBACK."
 
 (defun exwm-input--on-KeyPress (data _synthetic)
   "Handle KeyPress event."
-  (let ((obj (make-instance 'xcb:KeyPress)))
-    (xcb:unmarshal obj data)
-    (exwm--log "major-mode=%s buffer=%s"
-               major-mode (buffer-name (current-buffer)))
-    (if (derived-mode-p 'exwm-mode)
-        (cl-case exwm--input-mode
-          (line-mode
-           (exwm-input--on-KeyPress-line-mode obj data))
-          (char-mode
-           (exwm-input--on-KeyPress-char-mode obj data)))
-      (exwm-input--on-KeyPress-char-mode obj)))
-  (run-hooks 'exwm-input--event-hook))
+  (with-current-buffer (window-buffer (selected-window))
+    (let ((obj (make-instance 'xcb:KeyPress)))
+      (xcb:unmarshal obj data)
+      (exwm--log "major-mode=%s buffer=%s"
+                 major-mode (buffer-name (current-buffer)))
+      (if (derived-mode-p 'exwm-mode)
+          (cl-case exwm--input-mode
+            (line-mode
+             (exwm-input--on-KeyPress-line-mode obj data))
+            (char-mode
+             (exwm-input--on-KeyPress-char-mode obj data)))
+        (exwm-input--on-KeyPress-char-mode obj)))
+    (run-hooks 'exwm-input--event-hook)))
 
 (defun exwm-input--on-CreateNotify (data _synthetic)
   "Handle CreateNotify events."