#5133 Fix broken email threading for draft messages

extension/chrome/elements/compose-modules/compose-render-module.ts

@@ -98,9 +98,11 @@ export class ComposeRenderModule extends ViewModule<ComposeView> {
       const thread = await this.view.emailProvider.threadGet(this.view.threadId, 'metadata');
       const inReplyToMessage = thread.messages?.find(message => message.id === this.view.replyMsgId);
       if (inReplyToMessage) {
-        this.view.replyParams.inReplyTo = inReplyToMessage.payload?.headers?.find(
-          header => header.name === 'Message-Id' || header.name === 'Message-ID'
-        )?.value;
+        const msgId = inReplyToMessage.payload?.headers?.find(header => header.name === 'Message-Id' || header.name === 'Message-ID')?.value;
+        if (msgId) {
+          this.view.sendBtnModule.additionalMsgHeaders['In-Reply-To'] = msgId;
+          this.view.sendBtnModule.additionalMsgHeaders.References = msgId;
+        }
       }
       this.view.replyParams.subject = `${this.responseMethod === 'reply' ? 'Re' : 'Fwd'}: ${this.view.replyParams.subject}`;
       if (this.view.useFullScreenSecureCompose) {

extension/js/content_scripts/webmail/generic/webmail-element-replacer.ts

@@ -9,7 +9,7 @@ export abstract class WebmailElementReplacer {
   private replacePgpElsInterval: number;
 
   public abstract getIntervalFunctions: () => IntervalFunction[];
-  public abstract setReplyBoxEditable: () => Promise<void>;
+  public abstract setReplyBoxEditable: (messageContainer?: JQuery<Element>) => Promise<void>;
   public abstract reinsertReplyBox: (replyMsgId: string) => void;
   public abstract scrollToReplyBox: (replyMsgId: string) => void;
   public abstract scrollToCursorInReplyBox: (replyMsgId: string, cursorOffsetTop: number) => void;

extension/js/content_scripts/webmail/gmail/gmail-element-replacer.ts

@@ -85,10 +85,10 @@ export class GmailElementReplacer extends WebmailElementReplacer {
     ];
   };
 
-  public setReplyBoxEditable = async () => {
+  public setReplyBoxEditable = async (messageContainer?: JQuery<Element>) => {
     const replyContainerIframe = $('.reply_message_iframe_container > iframe').last();
-    if (replyContainerIframe.length) {
-      $(replyContainerIframe).replaceWith(this.factory.embeddedReply(this.getLastMsgReplyParams(this.getConvoRootEl(replyContainerIframe[0])), true)); // xss-safe-value
+    if (replyContainerIframe.length && messageContainer) {
+      $(replyContainerIframe).replaceWith(this.factory.embeddedReply(this.getLastMsgReplyParams(messageContainer), true)); // xss-safe-value
     } else {
       await this.replaceStandardReplyBox(undefined, true);
     }
@@ -351,10 +351,10 @@ export class GmailElementReplacer extends WebmailElementReplacer {
       return;
     }
     // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
-    const messageContainer = $(btn.closest('.h7')!);
+    const messageContainer: JQuery<Element> = $(btn.closest('.h7')!);
     if (messageContainer.is(':last-child')) {
       if (this.isEncrypted()) {
-        await this.setReplyBoxEditable();
+        await this.setReplyBoxEditable(messageContainer);
       } else {
         await this.replaceStandardReplyBox(undefined, true);
       }
@@ -589,8 +589,10 @@ export class GmailElementReplacer extends WebmailElementReplacer {
     return from ? Str.parseEmail(from) : undefined;
   };
 
-  private getLastMsgReplyParams = (convoRootEl: JQuery): FactoryReplyParams => {
-    return { replyMsgId: this.determineMsgId($(convoRootEl).find(this.sel.msgInner).last()) };
+  private getLastMsgReplyParams = (convoRootEl: JQuery<Element>): FactoryReplyParams => {
+    const msgIdElement = $(convoRootEl).find('[data-legacy-message-id], [data-message-id]');
+    const msgId = msgIdElement.attr('data-legacy-message-id') || msgIdElement.attr('data-message-id');
+    return { replyMsgId: msgId };
   };
 
   private getConvoRootEl = (anyInnerElement: HTMLElement) => {