Revert "Add `file-name-set-extension'"

This reverts commit 4f1a5e456e35930e8d0713b990bd7b14923cfe97.

2 files changed, 0 insertions, 34 deletions

diff --git a/lisp/files.el b/lisp/files.el
index 5fb9b9dcdcb..2450daf5bfc 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -4892,20 +4892,6 @@ extension, the value is \"\"."
         (if period
             "")))))
 
-(defun file-name-with-extension (filename extension)
-  "Set the EXTENSION of a FILENAME.
-Consolidates leading/trailing dots so that either `foo' or `.foo'
-can be passed as an EXTENSION.
-
-See also `file-name-sans-extension'."
-  (let* ((patt "[ .]+")
-         (file (string-trim-right filename patt))
-         (extn (string-trim-left extension patt)))
-    (cond ((string-empty-p file) (error "Malformed filename: %s" filename))
-          ((string-empty-p extn) (error "Malformed extension: %s" extension))
-          ((directory-name-p file) (error "Filename is a directory: %s" filename))
-          (t (concat (file-name-sans-extension file) "." extn)))))
-
 (defun file-name-base (&optional filename)
   "Return the base name of the FILENAME: no directory, no extension."
   (declare (advertised-calling-convention (filename) "27.1"))
diff --git a/test/lisp/files-tests.el b/test/lisp/files-tests.el
index 80f47a78dc8..dc96dff6398 100644
--- a/test/lisp/files-tests.el
+++ b/test/lisp/files-tests.el
@@ -1478,25 +1478,5 @@ The door of all subtleties!
                                (buffer-substring (point-min) (point-max))
                                nil nil)))))
 
-(ert-deftest files-tests-file-name-with-extension-good ()
-  "Test that `file-name-with-extension' succeeds with reasonable input."
-  (should (string= (file-name-with-extension "Jack" "css") "Jack.css"))
-  (should (string= (file-name-with-extension "Jack" ".css") "Jack.css"))
-  (should (string= (file-name-with-extension "Jack.scss" "css") "Jack.css"))
-  (should (string= (file-name-with-extension "Jack..." "...css") "Jack.css"))
-  (should (string= (file-name-with-extension "/path/to/Jack.md" "org") "/path/to/Jack.org")))
-
-(ert-deftest files-tests-file-name-with-extension-bad ()
-  "Test that `file-name-with-extension' fails on malformed input."
-  (should-error (file-name-with-extension nil nil))
-  (should-error (file-name-with-extension "Jack" nil))
-  (should-error (file-name-with-extension nil "css"))
-  (should-error (file-name-with-extension "" ""))
-  (should-error (file-name-with-extension "" "css"))
-  (should-error (file-name-with-extension "Jack" ""))
-  (should-error (file-name-with-extension "Jack" "..."))
-  (should-error (file-name-with-extension "..." "css"))
-  (should-error (file-name-with-extension "/is/a/directory/" "css")))
-
 (provide 'files-tests)
 ;;; files-tests.el ends here