[nongnu] elpa/rust-mode 4ec735e 300/486: Add stderr output from rustfmt on exit code 3

[ELPA Syncer]

branch: elpa/rust-mode
commit 4ec735e0fb993724fc264f6937267a898e30e6bf
Author: Christian Howe <cjhowe7@gmail.com>
Commit: Christian Howe <cjhowe7@gmail.com>

    Add stderr output from rustfmt on exit code 3
---
 rust-mode.el | 26 +++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/rust-mode.el b/rust-mode.el
index 1fce291..8d81efa 100644
--- a/rust-mode.el
+++ b/rust-mode.el
@@ -1195,13 +1195,25 @@ This is written mainly to be used as 
`end-of-defun-function' for Rust."
   (with-current-buffer (get-buffer-create "*rustfmt*")
     (erase-buffer)
     (insert-buffer-substring buf)
-    (let ((ret (call-process-region (point-min) (point-max) rust-rustfmt-bin t 
'(t nil) nil)))
-      (if (or (zerop ret) (= ret 3))
-          (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")))))
+    (let ((tmpf (make-temp-file "rustfmt")))
+      (let ((ret (call-process-region (point-min) (point-max) rust-rustfmt-bin
+                                      t `(t ,tmpf) nil)))
+        (format-message "%d" ret)
+        (cond
+         ((zerop ret)
+          (error "Rustfmt failed, see *rustfmt* buffer for details"))
+         ((= ret 3)
+          (if (not (string= (buffer-string)
+                            (with-current-buffer buf (buffer-string))))
+              (copy-to-buffer buf (point-min) (point-max)))
+          (erase-buffer)
+          (insert-file-contents tmpf)
+          (error "Rustfmt could not format some lines, see *rustfmt* buffer 
for details"))
+         (t
+          (if (not (string= (buffer-string)
+                            (with-current-buffer buf (buffer-string))))
+              (copy-to-buffer buf (point-min) (point-max)))
+          (kill-buffer)))))))
 
 (defconst rust--format-word 
"\\b\\(else\\|enum\\|fn\\|for\\|if\\|let\\|loop\\|match\\|struct\\|unsafe\\|while\\)\\b")
 (defconst rust--format-line "\\([\n]\\)")