[Bug] Dialog - Portal's container prop does not change the portal

[etn-tech]

Bug report

Current Behavior

The container prop of Dialog.Portal does not update the portal.

When opening the dialog, the body tag is still the element used for the portal element (See Stackblitz demo)

Code snippets

App.tsx :

DialogDemo.tsx :

Browser screenshots

Page before dialog open :

Page after dialog open :

Expected behavior

The div#root should be used as a the portal element. style="pointer-events: none;" & data-scroll-locked="&" should be on div#root.
The data-radix-focus-guards should be in div#root.

Reproducible example

Stackblitz demo

Suggested solution

In primitive/portal, we might check mounted is true
before containerProp.

// Before 
const container = containerProp || (mounted && globalThis?.document?.body);
// After 
const container = mounted && (containerProp || globalThis?.document?.body);

Not sure if it will be sufficient to fix the bug...

Additional context

—

Your environment

See Stackblitz demo

Software	Name(s)	Version
Radix Package(s)
React	19.1.0
Browser	Chrome 137.0
Assistive tech
Node	n/a
npm/yarn/pnpm	npm 10.8.2
Operating System	macOS 15.5

[sophie-meruscase]

Same issue.