Fix #2271: Editor infinite loop pasting HTML

components/lib/editor/Editor.js

@@ -62,12 +62,23 @@ export const Editor = React.memo(React.forwardRef((props, ref) => {
             quill.current.setContents(quill.current.clipboard.convert(props.value));
         }
 
-        quill.current.on('text-change', (delta, source) => {
+        quill.current.on('text-change', (delta, oldContents, source) => {
             let firstChild = contentRef.current.children[0];
             let html = firstChild ? firstChild.innerHTML : null;
             let text = quill.current.getText();
             if (html === '<p><br></p>') {
-                html = null;
+               html = null;
+            }
+
+            // GitHub #2271 prevent infinite loop on clipboard paste of HTML
+            if (source === "api") {
+                const htmlValue = contentRef.current.children[0];
+                const editorValue = document.createElement("div");
+                editorValue.innerHTML = props.value || "";
+                // this is necessary because Quill rearranged style elements
+                if (DomHandler.isEqualElement(htmlValue, editorValue)) {
+                    return;
+                }
             }
 
             if (props.onTextChange) {

components/lib/utils/DomHandler.js

@@ -953,4 +953,86 @@ export default class DomHandler {
             return ((element && element.nodeType === 9) || this.isExist(element)) ? element : null;
         }
     }
+
+    /**
+     * Get the attribute names for an element and sorts them alpha for comparison
+     */
+     static getAttributeNames(node) {
+        let index, rv, attrs;
+
+        rv = [];
+        attrs = node.attributes;
+        for (index = 0; index < attrs.length; ++index) {
+            rv.push(attrs[index].nodeName);
+        }
+        rv.sort();
+        return rv;
+    }
+
+    /**
+     * Compare two elements for equality.  Even will compare if the style element
+     * is out of order for example:
+     *
+     * elem1 = style="color: red; font-size: 28px"
+     * elem2 = style="font-size: 28px; color: red"
+     */
+     static isEqualElement(elm1, elm2) {
+        let attrs1, attrs2, name, node1, node2;
+
+        // Compare attributes without order sensitivity
+        attrs1 = DomHandler.getAttributeNames(elm1);
+        attrs2 = DomHandler.getAttributeNames(elm2);
+        if (attrs1.join(",") !== attrs2.join(",")) {
+            // console.log("Found nodes with different sets of attributes; not equiv");
+            return false;
+        }
+
+        // ...and values
+        // unless you want to compare DOM0 event handlers
+        // (onclick="...")
+        for (let index = 0; index < attrs1.length; ++index) {
+            name = attrs1[index];
+            if (name === 'style') {
+                const astyle = elm1.style;
+                const bstyle = elm2.style;
+                const rexDigitsOnly = /^\d+$/;
+                for (const key of Object.keys(astyle)) {
+                    if (!rexDigitsOnly.test(key) && astyle[key] !== bstyle[key]) {
+                        // Not equivalent, stop
+                        //console.log("Found nodes with mis-matched values for attribute '" + name + "'; not equiv");
+                        return false;
+                    }
+                }
+            } else {
+                if (elm1.getAttribute(name) !== elm2.getAttribute(name)) {
+                    // console.log("Found nodes with mis-matched values for attribute '" + name + "'; not equiv");
+                    return false;
+                }
+            }
+        }
+
+        // Walk the children
+        for (node1 = elm1.firstChild, node2 = elm2.firstChild; node1 && node2; node1 = node1.nextSibling, node2 = node2.nextSibling) {
+            if (node1.nodeType !== node2.nodeType) {
+                // display("Found nodes of different types; not equiv");
+                return false;
+            }
+            if (node1.nodeType === 1) { // Element
+                if (!DomHandler.isEqualElement(node1, node2)) {
+                    return false;
+                }
+            } else if (node1.nodeValue !== node2.nodeValue) {
+                // console.log("Found nodes with mis-matched nodeValues; not equiv");
+                return false;
+            }
+        }
+        if (node1 || node2) {
+            // One of the elements had more nodes than the other
+            // console.log("Found more children of one element than the other; not equivalent");
+            return false;
+        }
+
+        // Seem the same
+        return true;
+    }
 }