fix(emacs-pkgs/term-switcher): switch buffers by object, not name r/6518

The terminal switcher uses ivy to select buffers from a list of
buffer *names*, however this can cause weird situations if, for
example, two `vterm` sessions are in the same folder and buffer name
uniquification is active.

This commit implements a corrected solution, which constructs an
association list of buffer names to their actual buffer object, and
retrieves the buffer object from that list after the user has made
their selection. This way, changes in buffer names during terminal
selection do not lead to confusing results.

Change-Id: I3ab3d6b715b32606cf771dabc31d9d4507c8b856
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9145
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>

1 files changed, 13 insertions, 15 deletions

diff --git a/tools/emacs-pkgs/term-switcher/term-switcher.el b/tools/emacs-pkgs/term-switcher/term-switcher.el
index b7e4b049468e..9effac051ecc 100644
--- a/tools/emacs-pkgs/term-switcher/term-switcher.el
+++ b/tools/emacs-pkgs/term-switcher/term-switcher.el
@@ -27,18 +27,15 @@
   :type '(string)
   :group 'term-switcher)
 
-(defun ts/open-or-create-vterm (buffer-name)
-  "Switch to the buffer with BUFFER-NAME or create a new vterm
-  buffer."
-  (if (equal "New vterm" buffer-name)
-      ;; Don't open semi-broken vterms over tramp.
-      (if (file-remote-p default-directory)
-          (let ((default-directory "~"))
-            (vterm))
-        (vterm))
-    (if-let ((buffer (get-buffer buffer-name)))
-        (switch-to-buffer buffer)
-      (error "Could not find vterm buffer: %s" buffer-name))))
+(defun ts/open-or-create-vterm (buffer)
+  "Switch to the terminal in BUFFER, or create a new one if buffer is nil."
+  (if buffer
+      (switch-to-buffer buffer)
+    ;; Don't open semi-broken vterms over tramp.
+    (if (file-remote-p default-directory)
+        (let ((default-directory "~"))
+          (vterm))
+      (vterm))))
 
 (defun ts/is-vterm-buffer (buffer)
   "Determine whether BUFFER runs a vterm."
@@ -48,15 +45,16 @@
   "Switch to an existing vterm buffer or create a new one."
 
   (interactive)
-  (let ((terms (-map #'buffer-name
+  (let ((terms (-map (lambda (b) (cons (buffer-name b) b))
                      (-filter #'ts/is-vterm-buffer (buffer-list)))))
     (if terms
         (ivy-read "Switch to vterm: "
-                  (cons "New vterm" terms)
+                  (cons "New vterm" (-map #'car terms))
                   :caller 'ts/switch-to-terminal
                   :preselect (s-concat "^" term-switcher-buffer-prefix)
                   :require-match t
-                  :action #'ts/open-or-create-vterm)
+                  :action (lambda (match)
+                            (ts/open-or-create-vterm (cdr (assoc match terms)))))
       (vterm))))
 
 (provide 'term-switcher)