[FIX] discuss: clicking on attachment download closes current rtc call

Using <a> with 'download' attribute to download the attachment.
Prevent calling .navigate() interrupting the current call.

task-2692597

closes odoo/odoo#80903

X-original-commit: 97fa88c2e8407972c83c93d4d2198633a5560ecc
Signed-off-by: Sébastien Theys (seb) <seb@odoo.com>

addons/mail/static/src/components/attachment_viewer/attachment_viewer.js

@@ -139,8 +139,7 @@ export class AttachmentViewer extends Component {
      * @private
      */
     _download() {
-        const id = this.attachmentViewer.attachment.id;
-        this.env.services.navigate(`/web/content/ir.attachment/${id}/datas`, { download: true });
+        this.attachmentViewer.attachment.download();
     }
 
     /**

addons/mail/static/src/models/attachment/attachment.js

@@ -51,7 +51,12 @@ registerModel({
          * Send the attachment for the browser to download.
          */
         download() {
-            this.env.services.navigate(`/web/content/ir.attachment/${this.id}/datas`, { download: true });
+            const downloadLink = document.createElement('a');
+            downloadLink.setAttribute('href', `/web/content/ir.attachment/${this.id}/datas?download=true`);
+            // Adding 'download' attribute into a link prevents open a new tab or change the current location of the window.
+            // This avoids interrupting the activity in the page such as rtc call.
+            downloadLink.setAttribute('download', '');
+            downloadLink.click();
         },
         /**
          * Handles click on download icon.