Kill the partially created buffer when terminal creation quits

lisp/ghostel.el

@@ -5197,7 +5197,8 @@ spawn after initialization."
 DISPLAY-ACTION, when non-nil, is passed to `pop-to-buffer' before
 terminal creation so size detection observes the window that will
 display the terminal.  Optional ROWS and COLS are passed through to
-`ghostel--init-buffer'."
+`ghostel--init-buffer'.  If initialization is interrupted by an error
+or quit, the partially created buffer is killed before re-signaling."
   (let ((buffer (generate-new-buffer name)))
     (condition-case err
         (progn
@@ -5209,7 +5210,7 @@ display the terminal.  Optional ROWS and COLS are passed through to
             (pop-to-buffer buffer display-action))
           (ghostel--init-buffer buffer rows cols)
           buffer)
-      (error
+      ((error quit)
        (when (buffer-live-p buffer)
          (kill-buffer buffer))
        (signal (car err) (cdr err))))))

test/ghostel-project-test.el

@@ -295,6 +295,23 @@ same name must get separate buffers."
       (when (buffer-live-p buf)
         (kill-buffer buf)))))
 
+(ert-deftest ghostel-test-create-kills-buffer-on-quit ()
+  "`ghostel--create' kills the partially created buffer on quit.
+A keyboard quit can arrive during initialization, e.g. at a dir-locals
+prompt in `ghostel-mode'.  Uses `condition-case' directly since
+`should-error' only traps `error', not `quit'."
+  (cl-letf (((symbol-function 'ghostel--init-buffer)
+             (lambda (&rest _) (signal 'quit nil))))
+    (unwind-protect
+        (progn
+          (should (eq 'quit
+                      (condition-case err
+                          (progn (ghostel--create " *ghostel-test-quit*") nil)
+                        (quit (car err)))))
+          (should-not (get-buffer " *ghostel-test-quit*")))
+      (when-let* ((leftover (get-buffer " *ghostel-test-quit*")))
+        (kill-buffer leftover)))))
+
 (ert-deftest ghostel-test-returns-buffer ()
   "`ghostel' returns the (live) Ghostel buffer."
   (let ((created (generate-new-buffer "*ghostel-return-test*"))

test/ghostel-shell-test.el

@@ -119,8 +119,8 @@ newest-first list aligns with the buffer-order regions."
 				    ;; Send a real command before testing line editing.  The initial
 				    ;; output may be a terminal query or startup redraw; waiting for
 				    ;; command output proves fish's reader is accepting input.  Private
-				    ;; mode keeps history/autosuggestions from repainting `abc' after
-				    ;; it has been backspaced to `ab'.
+				    ;; mode keeps history/autosuggestions from repainting `wxyz' after
+				    ;; it has been backspaced to `wxy'.
 				    (ghostel--write-pty ghostel--term
 							"printf '%s%s\\n' GHOSTEL_FISH _READY\n")
 				    (ghostel-test--wait-until
@@ -129,25 +129,30 @@ newest-first list aligns with the buffer-order regions."
 						       (ghostel-test--rendered-terminal-text)))
 				     proc 10)
 
-				    ;; Type "abc" then backspace.
-				    (ghostel--write-pty ghostel--term "abc")
+				    ;; Type "wxyz" then backspace.  The typed text must
+				    ;; contain letters outside [0-9a-f]: fish's default
+				    ;; prompt shows the checkout's VCS state, and on a
+				    ;; detached HEAD (as in CI) that is the short commit
+				    ;; sha, so a hex-only marker can appear verbatim in
+				    ;; the prompt and never leave the screen.
+				    (ghostel--write-pty ghostel--term "wxyz")
 				    (ghostel-test--wait-until
 				     (lambda ()
-				       (string-match-p "abc" (ghostel-test--rendered-terminal-text)))
+				       (string-match-p "wxyz" (ghostel-test--rendered-terminal-text)))
 				     proc 5)
-				    (should (string-match-p "abc" (ghostel-test--rendered-terminal-text)))
+				    (should (string-match-p "wxyz" (ghostel-test--rendered-terminal-text)))
 
 				    ;; Send backspace (\x7f) and verify it works.
 				    (ghostel--write-pty ghostel--term "\x7f")
 				    (ghostel-test--wait-until
 				     (lambda ()
 				       (let ((state (ghostel-test--rendered-terminal-text)))
-					 (and (string-match-p "ab" state)
-					      (not (string-match-p "abc" state)))))
+					 (and (string-match-p "wxy" state)
+					      (not (string-match-p "wxyz" state)))))
 				     proc 5)
 				    (let ((state (ghostel-test--rendered-terminal-text)))
-				      (should (string-match-p "ab" state))
-				      (should-not (string-match-p "abc" state)))))))
+				      (should (string-match-p "wxy" state))
+				      (should-not (string-match-p "wxyz" state)))))))
 
 (ert-deftest ghostel-test-fish-auto-inject-loads-integration ()
   "Fish auto-inject shim chains to ghostel.fish and cleans XDG_DATA_DIRS."