Fix edit a reply in rich text editor

Author: florianduros

src/components/views/rooms/wysiwyg_composer/hooks/useInitialContent.ts

@@ -42,7 +42,8 @@ function parseEditorStateTransfer(
         // const restoredParts = this.restoreStoredEditorState(partCreator);
 
         if (editorStateTransfer.getEvent().getContent().format === 'org.matrix.custom.html') {
-            return editorStateTransfer.getEvent().getContent().formatted_body || "";
+            return editorStateTransfer.getEvent().getContent().formatted_body.replace(/<mx-reply>.*<\/mx-reply>/, '')
+                || "";
         }
 
         parts = parseEvent(editorStateTransfer.getEvent(), partCreator, {

test/components/views/rooms/wysiwyg_composer/EditWysiwygComposer-test.tsx

@@ -96,6 +96,32 @@ describe('EditWysiwygComposer', () => {
             await waitFor(() =>
                 expect(screen.getByRole('textbox')).toContainHTML(mockEvent.getContent()['body']));
         });
+
+        it('Should strip <mx-reply> tag from initial content', async () => {
+            // When
+            const mockEvent = mkEvent({
+                type: "m.room.message",
+                room: 'myfakeroom',
+                user: 'myfakeuser',
+                content: {
+                    "msgtype": "m.text",
+                    "body": "Replying to this",
+                    "format": "org.matrix.custom.html",
+                    "formatted_body": '<mx-reply>Reply</mx-reply>My content',
+                },
+                event: true,
+            });
+
+            const editorStateTransfer = new EditorStateTransfer(mockEvent);
+            customRender(false, editorStateTransfer);
+            await waitFor(() => expect(screen.getByRole('textbox')).toHaveAttribute('contentEditable', "true"));
+
+            // Then
+            await waitFor(() => {
+                expect(screen.getByRole('textbox')).not.toContainHTML("<mx-reply>Reply</mx-reply>");
+                expect(screen.getByRole('textbox')).toContainHTML("My content");
+            });
+        });
     });
 
     describe('Edit and save actions', () => {