Sidebar display bug

[noahfrederick]

The maximum allowed width of the sidebar is not wide enough to prevent scrolling horizontally. The blue "changed" indicator is only half visible:

Scrolling to the right reveals the rest of it:

Additionally, narrowing the sidebar hides more of the contents, as if the contents have a fixed width.

Expected behavior: The contents of the sidebar do not scroll horizontally. The blue "changed" indicator sticks to the right edge of the sidebar as it is resized.

Hardware: Mid-2010 MacBook Pro 17"
OS: Mavericks 10.9.1