* net/tramp.el (tramp-find-file-name-coding-system-alist): New

defun.
(tramp-handle-insert-file-contents, tramp-handle-write-region):
Use it.

1 files changed, 41 insertions, 19 deletions

diff --git a/lisp/net/tramp.el b/lisp/net/tramp.el
index d6d6a524be9..aaac6bfda88 100644
--- a/lisp/net/tramp.el
+++ b/lisp/net/tramp.el
@@ -3888,6 +3888,21 @@ This will break if COMMAND prints a newline, followed by the value of
             (t (tramp-make-tramp-file-name
                 multi-method method user host "")))))))
 
+(defun tramp-find-file-name-coding-system-alist (filename tmpname)
+  "Like `find-operation-coding-system' for Tramp filenames.
+Tramp's `insert-file-contents' and `write-region' work over
+temporary file names.  If `file-coding-system-alist' contains an
+expression, which matches more than the file name suffix, the
+coding system might not be determined.  This function repairs it."
+  (let (result)
+    (dolist (elt file-coding-system-alist result)
+      (when (and (consp elt) (string-match (car elt) filename))
+        ;; We found a matching entry in `file-coding-system-alist'.
+        ;; So we add a similar entry, but with the temporary file name
+        ;; as regexp.
+        (add-to-list
+         'result (cons (regexp-quote tmpname) (cdr elt)) 'append)))))
+
 (defun tramp-handle-insert-file-contents
   (filename &optional visit beg end replace)
   "Like `insert-file-contents' for tramp files."
@@ -3916,14 +3931,18 @@ This will break if COMMAND prints a newline, followed by the value of
         (tramp-message-for-buffer
          multi-method method user host
          9 "Inserting local temp file `%s'..." local-copy)
-        (setq result (insert-file-contents local-copy nil beg end replace))
-        (when visit
-          (setq buffer-file-name filename)
-          (set-visited-file-modtime)
-          (set-buffer-modified-p nil))
-        ;; Now `last-coding-system-used' has right value.  Remember it.
-        (when (boundp 'last-coding-system-used)
-          (setq coding-system-used (symbol-value 'last-coding-system-used)))
+        ;; We must ensure that `file-coding-system-alist' matches
+        ;; `local-copy'.
+        (let ((file-coding-system-alist
+               (tramp-find-file-name-coding-system-alist filename local-copy)))
+          (setq result (insert-file-contents local-copy nil beg end replace))
+          (when visit
+            (setq buffer-file-name filename)
+            (set-visited-file-modtime)
+            (set-buffer-modified-p nil))
+          ;; Now `last-coding-system-used' has right value.  Remember it.
+          (when (boundp 'last-coding-system-used)
+            (setq coding-system-used (symbol-value 'last-coding-system-used))))
         (tramp-message-for-buffer
          multi-method method user host
          9 "Inserting local temp file `%s'...done" local-copy)
@@ -4072,17 +4091,20 @@ Returns a file name in `tramp-auto-save-directory' for autosaving this file."
       ;; Set current buffer.  If connection wasn't open, `file-modes' has
       ;; changed it accidently.
       (set-buffer curbuf)
-      ;; We say `no-message' here because we don't want the visited file
-      ;; modtime data to be clobbered from the temp file.  We call
-      ;; `set-visited-file-modtime' ourselves later on.
-      (tramp-run-real-handler
-       'write-region
-       (if confirm ; don't pass this arg unless defined for backward compat.
-           (list start end tmpfil append 'no-message lockname confirm)
-         (list start end tmpfil append 'no-message lockname)))
-      ;; Now, `last-coding-system-used' has the right value.  Remember it.
-      (when (boundp 'last-coding-system-used)
-        (setq coding-system-used (symbol-value 'last-coding-system-used)))
+      ;; We say `no-message' here because we don't want the visited
+      ;; file modtime data to be clobbered from the temp file.  We
+      ;; call `set-visited-file-modtime' ourselves later on.  We must
+      ;; ensure that `file-coding-system-alist' matches `tmpfil'.
+      (let ((file-coding-system-alist
+             (tramp-find-file-name-coding-system-alist filename tmpfil)))
+        (tramp-run-real-handler
+         'write-region
+         (if confirm ; don't pass this arg unless defined for backward compat.
+             (list start end tmpfil append 'no-message lockname confirm)
+           (list start end tmpfil append 'no-message lockname)))
+        ;; Now, `last-coding-system-used' has the right value.  Remember it.
+        (when (boundp 'last-coding-system-used)
+          (setq coding-system-used (symbol-value 'last-coding-system-used))))
       ;; The permissions of the temporary file should be set.  If
       ;; filename does not exist (eq modes nil) it has been renamed to
       ;; the backup file.  This case `save-buffer' handles