* lisp/tar-mode.el (tar-extract): Call tar--try-jka-compr (bug#34251)

* lisp/tar-mode.el (tar--try-jka-compr): New function copied from
archive-try-jka-compr.

* lisp/arc-mode.el (archive-try-jka-compr): Set buffer-multibyte to t
instead of let-binding coding-system-for-read to 'no-conversion.

* test/data/decompress/tg.tar.gz:
* test/data/decompress/zg.zip: New fixtures.

* test/lisp/arc-mode-tests.el (arc-mode-test-zip-extract-gz):
* test/lisp/tar-mode-tests.el (tar-mode-test-tar-extract-gz): New tests.

* test/lisp/vc/diff-mode-tests.el (diff-mode-test-font-lock)
(diff-mode-test-font-lock-syntax-one-line): Skip unless shell and
diff executables are found.

1 files changed, 4 insertions, 0 deletions

diff --git a/test/lisp/vc/diff-mode-tests.el b/test/lisp/vc/diff-mode-tests.el
index 8e690548f05..8695d958bac 100644
--- a/test/lisp/vc/diff-mode-tests.el
+++ b/test/lisp/vc/diff-mode-tests.el
@@ -204,6 +204,8 @@ youthfulness
 
 (ert-deftest diff-mode-test-font-lock ()
   "Check font-locking of diff hunks."
+  (skip-unless (executable-find shell-file-name))
+  (skip-unless (executable-find diff-command))
   (let ((default-directory diff-mode-tests--datadir)
         (old "hello_world.c")
         (new "hello_emacs.c")
@@ -263,6 +265,8 @@ youthfulness
 
 (ert-deftest diff-mode-test-font-lock-syntax-one-line ()
   "Check diff syntax highlighting for one line with no newline at end."
+  (skip-unless (executable-find shell-file-name))
+  (skip-unless (executable-find diff-command))
   (let ((default-directory diff-mode-tests--datadir)
         (old "hello_world_1.c")
         (new "hello_emacs_1.c")