Yushun Cheng

Do not modify the buffer if yapf provides no change.

4

Currently the buffer being formatted will always be modified when `yapfify-region` is run. This patch simply checks whether any changes are made before modifying the buffer, avoiding unnecessary edits.

### Description #### Steps to Reproduce Load Org-roam, and run ```elisp (org-roam-db-update-file (concat org-roam-directory "/non-existent-file.org")) ``` #### Backtrace ``` Debugger entered--Lisp error: (file-missing "Opening input file" "No such file or...