field template fixup for modified templates only

ext/bg/js/options.js

@@ -269,11 +269,15 @@ function optionsVersion(options) {
             }
             options.general.compactTags = false;
             options.general.compactGlossaries = false;
-            options.anki.fieldTemplates = '{{#if merge}}\n' +
+            if (utilStringHashCode(options.anki.fieldTemplates) !== -1895236672) { // a3c8508031a1073629803d0616a2ee416cd3cccc
-                                        optionsFieldTemplates() +
+                options.anki.fieldTemplates = '{{#if merge}}\n' +
-                                        '\n{{else}}\n' +
+                                            optionsFieldTemplates() +
-                                        options.anki.fieldTemplates +
+                                            '\n{{else}}\n' +
-                                        '\n{{/if}}';
+                                            options.anki.fieldTemplates +
+                                            '\n{{/if}}';
+            } else {
+                options.anki.fieldTemplates = optionsFieldTemplates();
+            }
         }
     ];
 

ext/bg/js/util.js

@@ -52,6 +52,21 @@ function utilSetDifference(setA, setB) {
     );
 }
 
+function utilStringHashCode(string) {
+    let hashCode = 0;
+
+    if (string.length === 0) {
+        return hashCode;
+    }
+
+    for (let i = 0, charCode = string.charCodeAt(i); i < string.length; i++) {
+        hashCode = ((hashCode << 5) - hashCode) + charCode;
+        hashCode |= 0;
+    }
+
+    return hashCode;
+}
+
 function utilBackend() {
     return chrome.extension.getBackgroundPage().yomichan_backend;
 }