[mrholek]

React half of the same defect fixed for vanilla in coreui#1192. The Vue half is in coreui-vue.

What was wrong

The effect that locks body scroll had no cleanup, so unmounting an open offcanvas left overflow: hidden and the padding compensation on the body with nothing to undo them. The page stayed unscrollable. A route change that tears the tree down while the offcanvas is open is the ordinary way to reach this.

CModal next door already handles it — its effect ends in a cleanup that removes the same properties. This brings COffcanvas to the same shape.

Why it could not just be appended

The effect had an early return in the visible branch:

if (_visible && !scroll) {
  document.body.style.overflow = 'hidden'
  document.body.style.paddingRight = '0px'
  return            // ← returns undefined, so no cleanup is registered
}

React takes the effect's return value as the cleanup, so that branch registered none — in exactly the state the cleanup exists for. The lock and release are one if/else now, with the release repeated in the returned cleanup.

Test

An offcanvas rendered visible and then unmounted leaves no overflow or padding-right on the body. Verified red beforehand. Full suite green — 130 files, 402 tests.

Scope

coreui-react-pro carries the same file and is currently 0 commits behind, so it gets this through the next free→pro sync. v6 solved it differently: both frameworks moved to a shared useDialog hook whose unmount effect closes the dialog and clears the lock.