[elpa] externals/compat dd436797d1 1/6: Add make-lock-file-name

[ELPA Syncer]

branch: externals/compat
commit dd436797d16eda951c871cac370a5dadf654ce73
Author: Philip Kaludercic <philipk@posteo.net>
Commit: Philip Kaludercic <philipk@posteo.net>

    Add make-lock-file-name
---
 MANUAL          |  1 +
 compat-28.el    | 10 ++++++++++
 compat-tests.el | 17 +++++++++++++++++
 3 files changed, 28 insertions(+)

diff --git a/MANUAL b/MANUAL
index 5c202e9641..f7219f2cb1 100644
--- a/MANUAL
+++ b/MANUAL
@@ -395,6 +395,7 @@ provided by Compat by default:
 - Function: file-modes-number-to-symbolic :: See [[info:elisp#Changing 
Files][(elisp) Changing
   Files]].
 - Function: file-backup-file-names :: See [[info:elisp#Backup Names][(elisp) 
Backup Names]].
+- Function: make-lock-file-name :: Defined in ~files.el~.
 
 These functions are prefixed with ~compat~ prefix, and are only loaded
 when ~compat-28~ is required:
diff --git a/compat-28.el b/compat-28.el
index 2d6a55bf4e..2f8c330355 100644
--- a/compat-28.el
+++ b/compat-28.el
@@ -675,6 +675,16 @@ recent files are first."
           (push candidate files))))
     (sort files #'file-newer-than-file-p)))
 
+(compat-defun make-lock-file-name (filename)
+  "Make a lock file name for FILENAME.
+This prepends \".#\" to the non-directory part of FILENAME, and
+doesn't respect `lock-file-name-transforms', as Emacs 28.1 and
+onwards does."
+  (expand-file-name
+   (concat
+    ".#" (file-name-nondirectory filename))
+   (file-name-directory filename)))
+
 ;;;; Defined in minibuffer.el
 
 (compat-defun format-prompt (prompt default &rest format-args)
diff --git a/compat-tests.el b/compat-tests.el
index 6da09815c5..f59e33540b 100644
--- a/compat-tests.el
+++ b/compat-tests.el
@@ -1615,5 +1615,22 @@ being compared against."
   (ought "/:a" "/:a")
   (ought (concat "/ssh:" (system-name) ":/:a") "/ssh::a"))
 
+(compat-deftest make-lock-file-name
+  (ought (expand-file-name ".#") "")
+  (ought (expand-file-name ".#a") "a")
+  (ought (expand-file-name ".#foo") "foo")
+  (ought (expand-file-name ".#.") ".")
+  (ought (expand-file-name ".#.#") ".#")
+  (ought (expand-file-name ".#.a") ".a")
+  (ought (expand-file-name ".#.#") ".#")
+  (ought (expand-file-name "a/.#") "a/")
+  (ought (expand-file-name "a/.#b") "a/b")
+  (ought (expand-file-name "a/.#.#") "a/.#")
+  (ought (expand-file-name "a/.#.") "a/.")
+  (ought (expand-file-name "a/.#.b") "a/.b")
+  (ought (expand-file-name "a/.#foo") "a/foo")
+  (ought (expand-file-name "bar/.#b") "bar/b")
+  (ought (expand-file-name "bar/.#foo") "bar/foo"))
+
 (provide 'compat-tests)
 ;;; compat-tests.el ends here