We've found that the undocumented parameter section heading has different behaviors depending on what's focused at the moment before clicking. This is a bad sign, that we probably have two or more event handlers battling one another.
TBD @ECohen_WMDE: what is the ideal behavior?
What happens now:
Scenario: a multiple-template transclusion dialog is open, and the "Add undocumented parameter" heading is visible,
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1) Given that the content pane heading is collapsed and the heading is at the bottom of the screen and it is focused, when I click on the heading, then it expands and scrolls so the input is visible.
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2) Given that the content pane heading is collapsed and the heading is at the bottom of the screen and it not focused, when I click on the heading, then it expands but doesn't scroll.
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3) Given that the content pane heading is expanded and focus is on the heading or the input is visible on-screen, when I click on the heading then it collapses.
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4) Given that the content pane heading is expanded but the template name input is off-screen and not focused, when I click on the heading then the input scrolls onto the screen but does not collapse.
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@awight 's initial impression is that (2) is wrong and should behave like (1), and maybe (4) should behave like (3) but I'm not sure.