master a4dd94de80: Don't attempt to connect to a remote server during 'abbreviate-file-name'

[Stefan Monnier]

branch: master
commit a4dd94de8018e75fc5c000cff5f57b4a53f05042
Author: Jim Porter <jporterbugs@gmail.com>
Commit: Stefan Monnier <monnier@iro.umontreal.ca>

    Don't attempt to connect to a remote server during 'abbreviate-file-name'
    
    * lisp/net/tramp.el (tramp-handle-abbreviate-file-name): Only use the
    "home-directory" when a connection has been established.
---
 lisp/net/tramp.el | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/lisp/net/tramp.el b/lisp/net/tramp.el
index 32712efb3e..3c06ad1630 100644
--- a/lisp/net/tramp.el
+++ b/lisp/net/tramp.el
@@ -3343,16 +3343,24 @@ User is always nil."
   (let* ((case-fold-search (file-name-case-insensitive-p filename))
         (vec (tramp-dissect-file-name filename))
          (home-dir
-          (with-tramp-connection-property vec "home-directory"
-            (tramp-compat-funcall
-            'directory-abbrev-apply
-            (expand-file-name (tramp-make-tramp-file-name vec "~"))))))
+          (if (let ((non-essential t)) (tramp-connectable-p vec))
+              ;; If a connection has already been established, make
+              ;; sure the "home-directory" connection property is
+              ;; properly set.
+              (with-tramp-connection-property vec "home-directory"
+                (tramp-compat-funcall
+                'directory-abbrev-apply
+                (expand-file-name (tramp-make-tramp-file-name vec "~"))))
+            ;; Otherwise, just use the cached value.
+            (tramp-get-connection-property vec "home-directory" nil))))
     ;; If any elt of `directory-abbrev-alist' matches this name,
     ;; abbreviate accordingly.
     (setq filename (tramp-compat-funcall 'directory-abbrev-apply filename))
     ;; Abbreviate home directory.
-    (if (string-match
-        (tramp-compat-funcall 'directory-abbrev-make-regexp home-dir) filename)
+    (if (and home-dir
+             (string-match
+             (tramp-compat-funcall 'directory-abbrev-make-regexp home-dir)
+              filename))
         (tramp-make-tramp-file-name
         vec (concat "~" (substring filename (match-beginning 1))))
       (tramp-make-tramp-file-name (tramp-dissect-file-name filename)))))