[nongnu] elpa/rust-mode ba5ff90 260/486: Merge pull request #159 from hotpxl/master

[ELPA Syncer]

branch: elpa/rust-mode
commit ba5ff9058546df593ff7d8737fb52b5e92ad1913
Merge: b3b0f78 cffb950f2
Author: Niko Matsakis <niko@alum.mit.edu>
Commit: GitHub <noreply@github.com>

    Merge pull request #159 from hotpxl/master
    
    [master] Copy buffer only when format changes.
---
 rust-mode.el | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/rust-mode.el b/rust-mode.el
index 164c95b..6259b48 100644
--- a/rust-mode.el
+++ b/rust-mode.el
@@ -1258,8 +1258,10 @@ This is written mainly to be used as 
`end-of-defun-function' for Rust."
     (erase-buffer)
     (insert-buffer-substring buf)
     (if (zerop (call-process-region (point-min) (point-max) rust-rustfmt-bin t 
t nil))
-        (progn (copy-to-buffer buf (point-min) (point-max))
-               (kill-buffer))
+        (progn
+          (if (not (string= (buffer-string) (with-current-buffer buf 
(buffer-string))))
+              (copy-to-buffer buf (point-min) (point-max)))
+          (kill-buffer))
       (error "Rustfmt failed, see *rustfmt* buffer for details"))))
 
 (defun rust-format-buffer ()