with-connection-local-variables: Avoid code duplication

Move the bulk of the code of `with-connection-local-variables` into
a separate function, which both avoids duplicating that code but also
avoids duplicating the code passed as the body of
a `with-connection-local-variables`.  Also makes it easier to
debug the code, or change the implementation of
`with-connection-local-variables` without having to recompile all
the users.

* lisp/files-x.el (with-connection-local-variables-1): New function,
extracted from `with-connection-local-variables`.
(with-connection-local-variables): Use it.

1 files changed, 22 insertions, 16 deletions

diff --git a/lisp/files-x.el b/lisp/files-x.el
index 0ae9fb076eb..4db6fbd22cc 100644
--- a/lisp/files-x.el
+++ b/lisp/files-x.el
@@ -740,22 +740,28 @@ If APPLICATION is nil, `connection-local-default-application' is used."
   "Apply connection-local variables according to `default-directory'.
 Execute BODY, and unwind connection-local variables."
   (declare (debug t))
-  `(if (file-remote-p default-directory)
-       (let ((enable-connection-local-variables t)
-             (old-buffer-local-variables (buffer-local-variables))
-             connection-local-variables-alist)
-         (hack-connection-local-variables-apply
-          (connection-local-criteria-for-default-directory))
-         (unwind-protect
-             (progn ,@body)
-           ;; Cleanup.
-           (dolist (variable connection-local-variables-alist)
-             (let ((elt (assq (car variable) old-buffer-local-variables)))
-               (if elt
-                   (set (make-local-variable (car elt)) (cdr elt))
-                 (kill-local-variable (car variable)))))))
-     ;; No connection-local variables to apply.
-     ,@body))
+  `(with-connection-local-variables-1 (lambda () ,@body)))
+
+;;;###autoload
+(defun with-connection-local-variables-1 (body-fun)
+  "Apply connection-local variables according to `default-directory'.
+Call BODY-FUN with no args, and then unwind connection-local variables."
+  (if (file-remote-p default-directory)
+      (let ((enable-connection-local-variables t)
+            (old-buffer-local-variables (buffer-local-variables))
+            connection-local-variables-alist)
+        (hack-connection-local-variables-apply
+         (connection-local-criteria-for-default-directory))
+        (unwind-protect
+            (funcall body-fun)
+          ;; Cleanup.
+          (dolist (variable connection-local-variables-alist)
+            (let ((elt (assq (car variable) old-buffer-local-variables)))
+              (if elt
+                  (set (make-local-variable (car elt)) (cdr elt))
+                (kill-local-variable (car variable)))))))
+    ;; No connection-local variables to apply.
+    (funcall body-fun)))
 
 ;;;###autoload
 (defun path-separator ()