[Popover] Cannot get to all menu items if there are many menu items and scrollable container is not scrollable

[jamespizzurro]

Problem description

It seems #7472 caused the rendering of popovers with enough menu items to fill the browser viewport not to size properly, and as a result some items are cut off if the scrollable container of the popover cannot actually be scrolled. For example, if the scrollable container is set to 'window', but the window is not scrollable and there are sufficient menu items in the popover menu to fill the screen, some menu items cannot be scrolled to inside the popover and selected. Specifically, #7472 removed the 'Math.max' bit, removing the clamp to 0. Adding this back in resolves this issue for me.

Perhaps another prop could be added to the Popover component so that it is capable of behaving the way it behaved before with the 0 clamping?

Link to minimal working code that reproduces the issue

https://www.webpackbin.com/bins/-Kq4OpZRwiDD_HbDEBH-

Click the 'Add' button and observe the popup isn't positioned correctly, and scrolling it works, but does not fix the positioning so you aren't able to select some menu options. Note that this is a problem because the body is not scrollable in this example, which means there's no way to reveal the menu items you can't get to.

Versions

• Material-UI: 0.18.7
• React: 15.6.1
• Browser: All browsers suspected, but observed in Google Chrome Version 60.0.3112.78 (Official Build) (64-bit), Safari for iOS (unknown version), Google Chrome for iOS (unknown version), Google Chrome for Android (unknown version)