Kendo-ui-core: Multiple unexpected k-overlay div elements added to Window with iframe true

[Dimitar-Goshev]

Bug report

Multiple unexpected k-overlay div elements added to iframe Windows on the background on using toFront() method of another Window or clicking on Window title bar. As a result, multiple unexpected and unnecessary elements are added to Windows on the background.

Ticket ID: 1431891

Reproduction of the problem - toFront method

1. Run the following Dojo snippet

2. Inspect the div with id="window1" by using the dev tools picker for elements to avoid clicking with right mouse button on a window.
   The div has 1 iframe child element followed by 1 element <div class="k-overlay"</div>
   

3. Click on "Bring Window 2 to front." button 3 times, which calls toFront() method of Window 2.

Current behavior

Element <div class="k-overlay"</div> is added to id="window1" div on each call of toFront().
Now there are total of 4 divs:

Expected/desired behavior

The window with id="window1" has only 1 element <div class="k-overlay"</div>

Reproduction of the problem - clicking on Window title bar

1. Run the following Dojo snippet

2. Inspect the div with id="window1" by using the dev tools picker for elements to avoid clicking with right mouse button on a window.
   The div has 1 iframe child element followed by 1 element <div class="k-overlay"</div>
   

3. Click on Window 2 title bar.

Current behavior

Each click on Window 2 title bar adds 2 <div class="k-overlay"</div> elements to id="window1"
Now there are total of 3 divs.

Expected/desired behavior

The window with id="window1" has only 1 element <div class="k-overlay"</div>

Environment

• Kendo UI version: 2020.2.513
• Browser: all

[M-Rostock]

What is the status of this issue?

I'm having the same issue and it is preventing the use of multiple windows altogether.

Opening more than two windows results in a behaviour where you cannot access the third+ windows - and clicking outside the frontmost window toggles focus to the other window.

[Dimitar-Goshev]

@M-Rostock The issue is reproducible with our latest version 2020.2.513 as well. I updated its priority label as you are experiencing it as well. Keep track on this issue's status to be informed about its progress.