blank lines get deminished and appear again

src/templates/html.rs

@@ -91,18 +91,18 @@ const JS_SCRIPT_VIEWSPECS: &str = r##"
         innerElements.forEach(element => {
             element.style.display = 'none';
         });
-        
+
         zoom_ins.forEach(element => {
             element.style.display = 'none';
         });
-        
+
         zoom_outs.forEach(element => {
             element.style.display = 'block';
         });
 
         document.getElementById(body_id).style.display = 'block';
         document.getElementById(summary_id).style.display = 'block';
-        
+
         window.scrollTo(0, 0);
     }
 
@@ -119,15 +119,15 @@ const JS_SCRIPT_VIEWSPECS: &str = r##"
         innerElements.forEach(element => {
             element.style.display = 'none';
         });
-        
+
         zoom_ins.forEach(element => {
             element.style.display = 'block';
         });
-        
+
         zoom_outs.forEach(element => {
             element.style.display = 'none';
         });
-        
+
         window.scrollTo(0, 0);
     }
 
@@ -172,19 +172,26 @@ const JS_SCRIPT_VIEWSPECS: &str = r##"
                     const content = window.opener.document.getElementById('content');
 
                     if (blankLinesCheckbox.checked) {
-                        // Restore original <br> elements
-                        window.opener.originalBrElements.forEach(br => {
-                            const parent = br.parentNode;
-                            parent.insertBefore(br.element, parent.children[br.index]);
-                        });
-                        window.opener.originalBrElements = [];
 
-                        // Restore original margins
-                        window.opener.originalStyles.forEach(item => {
-                            item.element.style.marginTop = item.styles.marginTop;
-                            item.element.style.marginBottom = item.styles.marginBottom;
-                        });
-                        window.opener.originalStyles = [];
+                        if (window.opener.originalBrElements) {
+                            window.opener.originalBrElements.forEach(br => {
+                                const parent = br.parent; // Use the correct parent reference
+
+                                if (parent) { // Ensure parent is defined
+                                    parent.insertBefore(br.element, parent.children[br.index]);
+                                }
+                            });
+                            window.opener.originalBrElements = []; // Clear the array after restoration
+                        }
+
+                        if (window.opener.originalStyles) {
+                            window.opener.originalStyles.forEach(item => {
+
+                                item.element.style.marginTop = item.styles.marginTop;
+                                item.element.style.marginBottom = item.styles.marginBottom;
+                            });
+                            window.opener.originalStyles = []; // Clear the array after restoration
+                        }
                     } else {
                         // Remove all <br> elements
                         const brElements = content.querySelectorAll('br');