[elpa] externals/persist 2719b2d3c0: Persist variables that have changed back to default values

[Lars Ingebrigtsen]

branch: externals/persist
commit 2719b2d3c006f3963face1ad27fcadf1490d8efc
Author: Gulshan Singh <gsingh2011@gmail.com>
Commit: Lars Ingebrigtsen <larsi@gnus.org>

    Persist variables that have changed back to default values
    
    * persist.el (persist-save): Persist variables that have changed
    back to default values (bug#54346).
    
    Copyright-paperwork-exempt: yes
---
 persist.el            | 38 ++++++++++++++++++++------------------
 test/persist-tests.el |  3 +++
 2 files changed, 23 insertions(+), 18 deletions(-)

diff --git a/persist.el b/persist.el
index 3d8d1af5ce..950de3a231 100644
--- a/persist.el
+++ b/persist.el
@@ -132,24 +132,26 @@ variables persist automatically when Emacs exits."
   (unless (persist--persistant-p symbol)
     (error (format
             "Symbol %s is not persistant" symbol)))
-  (unless (equal (symbol-value symbol)
-                 (persist-default symbol))
-    (let ((dir-loc
-           (file-name-directory
-            (persist--file-location symbol))))
-      (unless (file-exists-p dir-loc)
-        (mkdir dir-loc)))
-    (with-temp-buffer
-      (let (print-level
-           print-length
-            print-quoted
-            (print-escape-control-characters t)
-            (print-escape-nonascii t)
-            (print-circle t))
-       (print (symbol-value symbol) (current-buffer)))
-      (write-region (point-min) (point-max)
-                    (persist--file-location symbol)
-                    nil 'quiet))))
+  (let ((symbol-file-loc (persist--file-location symbol)))
+    (if (equal (symbol-value symbol)
+               (persist-default symbol))
+        (when (file-exists-p symbol-file-loc)
+          (delete-file symbol-file-loc))
+      (let ((dir-loc
+             (file-name-directory symbol-file-loc)))
+        (unless (file-exists-p dir-loc)
+          (mkdir dir-loc))
+        (with-temp-buffer
+          (let (print-level
+                print-length
+                print-quoted
+                (print-escape-control-characters t)
+                (print-escape-nonascii t)
+                (print-circle t))
+            (print (symbol-value symbol) (current-buffer)))
+          (write-region (point-min) (point-max)
+                        symbol-file-loc
+                        nil 'quiet))))))
 
 (defun persist-default (symbol)
   "Return the default value for SYMBOL."
diff --git a/test/persist-tests.el b/test/persist-tests.el
index 9fa406f4d9..b6645a9297 100644
--- a/test/persist-tests.el
+++ b/test/persist-tests.el
@@ -44,6 +44,9 @@
        (with-temp-buffer
          (insert-file-contents (persist--file-location sym))
          (buffer-string))))
+     (set sym 10)
+     (persist-save sym)
+     (should-not (file-exists-p (persist--file-location sym)))
      (should-error
       (persist-save 'fred)))))