diff options
| -rw-r--r-- | apheleia.el | 65 |
1 files changed, 35 insertions, 30 deletions
diff --git a/apheleia.el b/apheleia.el index e46898b..9b5885e 100644 --- a/apheleia.el +++ b/apheleia.el @@ -44,9 +44,6 @@ (buffer-hash) (md5 (current-buffer)))) -(defvar apheleia--buffer-hash nil - "Return value of `buffer-hash' when formatter started running.") - (defun apheleia--disallowed-p () "Return an error message if Apheleia cannot be run, else nil." (when (and buffer-file-name @@ -96,33 +93,41 @@ changes), CALLBACK, if provided, is invoked with no arguments." ;; error on `post-command-hook'. We already took care of throwing ;; `user-error' on interactive usage above. (unless (apheleia--disallowed-p) - (setq-local apheleia--buffer-hash (apheleia--buffer-hash)) - (let ((cur-buffer (current-buffer)) - (remote (file-remote-p (or buffer-file-name - default-directory)))) - (apheleia--run-formatters - formatters - cur-buffer - remote - (lambda (formatted-buffer) - (when (buffer-live-p cur-buffer) - (with-current-buffer cur-buffer - ;; Short-circuit. - (when - (equal - apheleia--buffer-hash (apheleia--buffer-hash)) - (apheleia--create-rcs-patch - cur-buffer formatted-buffer remote - (lambda (patch-buffer) - (when (buffer-live-p cur-buffer) - (with-current-buffer cur-buffer - (when - (equal - apheleia--buffer-hash (apheleia--buffer-hash)) - (apheleia--apply-rcs-patch - (current-buffer) patch-buffer) - (when callback - (funcall callback)))))))))))))))) + ;; It's important to store the saved buffer hash in a lexical + ;; variable rather than a dynamic (global) one, else multiple + ;; concurrent invocations of `apheleia-format-buffer' can + ;; overwrite each other, and get the wrong results about whether + ;; the buffer was actually modified since the formatting + ;; operation started, leading to data loss. + ;; + ;; https://github.com/radian-software/apheleia/issues/226 + (let ((saved-buffer-hash (apheleia--buffer-hash))) + (let ((cur-buffer (current-buffer)) + (remote (file-remote-p (or buffer-file-name + default-directory)))) + (apheleia--run-formatters + formatters + cur-buffer + remote + (lambda (formatted-buffer) + (when (buffer-live-p cur-buffer) + (with-current-buffer cur-buffer + ;; Short-circuit. + (when + (equal + saved-buffer-hash (apheleia--buffer-hash)) + (apheleia--create-rcs-patch + cur-buffer formatted-buffer remote + (lambda (patch-buffer) + (when (buffer-live-p cur-buffer) + (with-current-buffer cur-buffer + (when + (equal + saved-buffer-hash (apheleia--buffer-hash)) + (apheleia--apply-rcs-patch + (current-buffer) patch-buffer) + (when callback + (funcall callback))))))))))))))))) (defcustom apheleia-post-format-hook nil "Normal hook run after Apheleia formats a buffer successfully." |