From 53e166cb0c7c2624a5a54edafe8828d7b7edc612 Mon Sep 17 00:00:00 2001
From: Joseph Turner <joseph@breatheoutbreathe.in>
Date: Tue, 23 May 2023 13:09:29 -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            | 16 +++++++++++-----
 test/persist-tests.el |  8 ++++++++
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/persist.el b/persist.el
index 0069273ca2..725f2f71cf 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."
@@ -132,9 +134,13 @@ (defun persist-save (symbol)
   (unless (persist--persistant-p 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))
+  (let ((symbol-file-loc (persist--file-location symbol))
+        (value (symbol-value symbol))
+        (default (persist-default symbol)))
+    (if (if (and (hash-table-p value)
+                 (hash-table-p default))
+            (persist-hash-equal value default)
+          (equal value default))
         (when (file-exists-p symbol-file-loc)
           (delete-file symbol-file-loc))
       (let ((dir-loc
@@ -148,7 +154,7 @@ (defun persist-save (symbol)
                 (print-escape-control-characters t)
                 (print-escape-nonascii t)
                 (print-circle t))
-            (print (symbol-value symbol) (current-buffer)))
+            (print value (current-buffer)))
           (write-region (point-min) (point-max)
                         symbol-file-loc
                         nil 'quiet))))))
diff --git a/test/persist-tests.el b/test/persist-tests.el
index 0a85b78767..8a30a24e23 100644
--- a/test/persist-tests.el
+++ b/test/persist-tests.el
@@ -61,6 +61,14 @@ (ert-deftest test-persist-save-string ()
   "Test saving string."
   (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)))
+    (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)))
-- 
2.40.1