Windows 10, GTX 650
Broken: 2.77 22a2853
Short description of error
When User Preferences -> Input -> Select With -> Left is chosen, solved tracks in the dopesheet view of the Movie Clip Editor window cannot be selected with the left mouse button and must be selected with the right mouse button.
Exact steps for others to reproduce the error
Change user interface to select with the left mouse button in a scene that has motion-tracked points. Switch to the dopeview editor. Notice that tracks only highlight with the right mouse button, not the left mouse button.