Bug 879255:  Refactor fix for bug 613888, step 1:  create haveCurrentTransition variable.  r=nrc
Bug 879255:  Refactor fix for bug 613888, step 2:  consolidate oldPT variable.  r=nrc
Bug 879255:  Refactor fix for bug 613888, step 3:  move no-change test earlier so that we don't have to clutter conditions between the new location and old with logic to fall through to it.  r=nrc
Bug 879255:  Refactor fix for bug 613888, step 4:  consolidate conditions, and reindent (and fix bracing while doing so).  r=nrc