From 11194569423dcdf8778a55f59dbca8f49e8b7b37 Mon Sep 17 00:00:00 2001
From: Joseph Turner <joseph@breatheoutbreathe.in>
Date: Sun, 3 Sep 2023 17:10:38 -0700
Subject: [PATCH 3/5] Make persist-defvar work with hash tables

Previously, when persist-defvar received a hash table for an initial
value, updated values were not persisted.

* persist.el (persist-symbol): Use hash table copy as default so that
the original table can be modified without modifying the default value.
(persist-save): Use persist-equal to ensure that hash tables are
correctly compared
* test/persist-tests.el (test-persist-save-hash): Test hash tables
persistence.
---
 persist.el            | 8 +++++---
 test/persist-tests.el | 8 ++++++++
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/persist.el b/persist.el
index a707d038cd..7b2ab491d7 100644
--- a/persist.el
+++ b/persist.el
@@ -118,7 +118,9 @@ (defun persist-symbol (symbol &optional initvalue)
   (let ((initvalue (or initvalue (symbol-value symbol))))
     (add-to-list 'persist--symbols symbol)
     (put symbol 'persist t)
-    (put symbol 'persist-default initvalue)))
+    (if (hash-table-p initvalue)
+        (put symbol 'persist-default (copy-hash-table initvalue))
+      (put symbol 'persist-default initvalue))))
 
 (defun persist--persistant-p (symbol)
   "Return non-nil if SYMBOL is a persistant variable."
@@ -133,8 +135,8 @@ (defun persist-save (symbol)
     (error (format
             "Symbol %s is not persistant" symbol)))
   (let ((symbol-file-loc (persist--file-location symbol)))
-    (if (equal (symbol-value symbol)
-               (persist-default symbol))
+    (if (persist-equal (symbol-value symbol)
+                       (persist-default symbol))
         (when (file-exists-p symbol-file-loc)
           (delete-file symbol-file-loc))
       (let ((dir-loc
diff --git a/test/persist-tests.el b/test/persist-tests.el
index f2b04769ef..90adf1c6d6 100644
--- a/test/persist-tests.el
+++ b/test/persist-tests.el
@@ -61,6 +61,14 @@ (ert-deftest test-persist-save-string ()
   "Test saving string."
   (persist-test-persist-save "foo" "foo" (set sym "bar") "bar"))
 
+(ert-deftest test-persist-save-hash ()
+  "Test saving hash table."
+  (let* ((hash (make-hash-table))
+         (default (copy-hash-table hash)))
+    (persist-test-persist-save hash default
+                               (puthash 'foo "bar" (symbol-value sym))
+                               "#s(hash-table size 65 test eql rehash-size 1.5 rehash-threshold 0.8125 data (foo \"bar\"))")))
+
 (ert-deftest test-persist-load ()
   (with-local-temp-persist
    (let ((sym (cl-gensym)))
-- 
2.41.0