Autoload tramp-archive

* doc/misc/tramp.texi (Archive file names): Do not require to
load Tramp explicitly, this is autoloaded now also for file archives.

* lisp/net/tramp-archive.el (tramp-archive-suffixes)
(tramp-archive-compression-suffixes): Autoload them.
(tramp-archive-autoload-file-name-regexp): New defmacro.
(tramp-archive-file-name-regexp): Use it.
(tramp-register-archive-file-name-handler): New defun.  Call
it in `after-init-hook'.

* test/lisp/net/tramp-archive-tests.el
(tramp-archive-test40-file-system-info): Rename from
`tramp-archive-test40-archive-file-system-info.
(tramp-archive-test42-auto-load)
(tramp-archive-test42-delay-load): New tests.

1 files changed, 51 insertions, 1 deletions

diff --git a/test/lisp/net/tramp-archive-tests.el b/test/lisp/net/tramp-archive-tests.el
index 96c6a71097c..bebdf108c66 100644
--- a/test/lisp/net/tramp-archive-tests.el
+++ b/test/lisp/net/tramp-archive-tests.el
@@ -779,7 +779,7 @@ This tests also `file-executable-p', `file-writable-p' and `set-file-modes'."
     (delete-directory tmp-file)
     (should-not (file-exists-p tmp-file))))
 
-(ert-deftest tramp-archive-test40-archive-file-system-info ()
+(ert-deftest tramp-archive-test40-file-system-info ()
   "Check that `file-system-info' returns proper values."
   (skip-unless tramp-gvfs-enabled)
   ;; Since Emacs 27.1.
@@ -796,6 +796,56 @@ This tests also `file-executable-p', `file-writable-p' and `set-file-modes'."
                  (zerop (nth 1 fsi))
                  (zerop (nth 2 fsi))))))
 
+(ert-deftest tramp-archive-test42-auto-load ()
+  "Check that `tramp-archive' autoloads properly."
+  (skip-unless tramp-gvfs-enabled)
+
+  (let ((default-directory (expand-file-name temporary-file-directory))
+        (code
+         (format
+          "(message \"Tramp loaded: %%s\" (and (file-exists-p %S) t))"
+          tramp-archive-test-archive)))
+    (should
+     (string-match
+      "Tramp loaded: t[\n\r]+"
+      (shell-command-to-string
+       (format
+        "%s -batch -Q -L %s --eval %s"
+        (shell-quote-argument
+         (expand-file-name invocation-name invocation-directory))
+        (mapconcat 'shell-quote-argument load-path " -L ")
+        (shell-quote-argument code)))))))
+
+(ert-deftest tramp-archive-test42-delay-load ()
+  "Check that `tramp-archive' is loaded lazily, only when needed."
+  (skip-unless tramp-gvfs-enabled)
+
+  ;; Tramp is neither loaded at Emacs startup, nor when completing a
+  ;; non archive file name like "/foo".  Completing an archive file
+  ;; name like "/foo.tar/" autoloads Tramp, when `tramp-mode' is t.
+  (let ((default-directory (expand-file-name temporary-file-directory))
+        (code
+         (format
+          "(progn \
+            (message \"Tramp loaded: %%s\" (featurep 'tramp-archive)) \
+            (file-name-all-completions %S \"/\") \
+            (message \"Tramp loaded: %%s\" (featurep 'tramp-archive)) \
+            (file-name-all-completions %S \"/\") \
+            (message \"Tramp loaded: %%s\" (featurep 'tramp-archive)))"
+          tramp-archive-test-file-archive
+          tramp-archive-test-archive)))
+    ;; Tramp doesn't load when `tramp-mode' is nil.
+    (should
+     (string-match
+      "Tramp loaded: nil[\n\r]+Tramp loaded: nil[\n\r]+Tramp loaded: t[\n\r]+"
+      (shell-command-to-string
+       (format
+        "%s -batch -Q -L %s --eval %s"
+        (shell-quote-argument
+         (expand-file-name invocation-name invocation-directory))
+        (mapconcat 'shell-quote-argument load-path " -L ")
+        (shell-quote-argument code)))))))
+
 (ert-deftest tramp-archive-test99-libarchive-tests ()
   "Run tests of libarchive test files."
   :tags '(:expensive-test)