fix(control): Making titlebarbutton nullable in TitleBar.cs

[dkuaf]

Nullable check for titlebarbutton

Pull request type

Please check the type of change your PR introduces:

• Update
• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes

What is the current behavior?

nullref exception when TitleBar.Visibilty = Collapsed

Issue Number: #1670
fixes #1670

What is the new behavior?

early return on null

Other information

n/a

[luca-domenichini]

Hi @dkuaf , there is already #1671 that addresses this issue.
In my PR I made the fewest possible changes in order to address the issue.
Maybe I can merge my PR with your changes too, since it seems they makes sense.
I usually hesitate to make too many changes and prefer to wait for maintainers reaction on first impl.
Drop a comment there if you like.

[dkuaf]

Hi @dkuaf , there is already #1671 that addresses this issue. In my PR I made the fewest possible changes in order to address the issue. Maybe I can merge my PR with your changes too, since it seems they makes sense. I usually hesitate to make too many changes and prefer to wait for maintainers reaction on first impl. Drop a comment there if you like.

sorry i did not know that issue had an pr, i did not see a link on the issue to an open PR

i am closing this (i think nullable change make sense)