Open Radar

 
On viewing certain emails, when I click the "..." to view quoted content, nothing appears to happen. When I then click on another message, it does not display in the conversation view. Instead, the old message (the one where clicking "..." did nothing) cotinues to be displayed. Scrolling and clicking does nothing. If I shrink the width of the Mailbox List, I can see another conversation view beneath the frozen one. Quitting and restarting Mail is the only way to get this back.

I have not been able to determine any kind of pattern regarding which emails trigger this.

Console showed this error:
1/13/14 2:20:01.626 PM Mail[62802]: [WEB BUNDLE] Could not execute script: TypeError: 'undefined' is not a function (evaluating 'e.getBoundingClientRect()')

Later I got this message 4 times in a row. Not sure if they're related:
1/13/14 2:23:25.530 PM Mail[62802]: Unable to simultaneously satisfy constraints:
(
    "<NSLayoutConstraint:0x600001095860 H:|-(0)-[NSScrollView:0x6000001daa90]   (Names: '|':MessageView:0x6000003323e0 )>",
    "<NSLayoutConstraint:0x600001095950 NSScrollView:0x6000001daa90.trailing == MessageView:0x6000003323e0.trailing>",
    "<NSAutoresizingMaskLayoutConstraint:0x600000294d20 h=-&- v=--& H:|-(0)-[ConversationView]   (Names: ConversationView:0x7ff1f2492a10, '|':NSClipView:0x7ff1f2563530 )>",
    "<NSLayoutConstraint:0x60800109fbd0 H:|-(0)-[MessageView:0x6000003323e0]   (Names: '|':ConversationCellView:0x6000003a93e0 )>",
    "<NSLayoutConstraint:0x60800109ed20 H:[MessageView:0x6000003323e0]-(0)-|   (Names: '|':ConversationCellView:0x6000003a93e0 )>",
    "<NSLayoutConstraint:0x6080010943c0 ConversationCellView:0x6000003a93e0.width == ConversationView.width   (Names: ConversationView:0x7ff1f2492a10 )>",
    "<NSAutoresizingMaskLayoutConstraint:0x600000291fd0 h=-&- v=--& H:[ConversationView]-(0)-|   (Names: ConversationView:0x7ff1f2492a10, '|':NSClipView:0x7ff1f2563530 )>",
    "<NSAutoresizingMaskLayoutConstraint:0x600000293bf0 h=-&- v=-&- H:|-(0)-[NSClipView:0x7ff1f2563530]   (Names: '|':NSScrollView:0x6000001dc7a0 )>",
    "<NSAutoresizingMaskLayoutConstraint:0x6000002853c0 h=-&- v=-&- H:[NSClipView:0x7ff1f2563530]-(15)-|   (Names: '|':NSScrollView:0x6000001dc7a0 )>",
    "<NSLayoutConstraint:0x60000109c7f0 H:|-(0)-[NSScrollView:0x6000001dc7a0]   (Names: '|':ViewingPaneView:0x608000196f40 )>",
    "<NSLayoutConstraint:0x60000109d1f0 H:[NSScrollView:0x6000001dc7a0]-(0)-|   (Names: '|':ViewingPaneView:0x608000196f40 )>",
    "<NSAutoresizingMaskLayoutConstraint:0x6000002946e0 h=--& v=--& H:[ViewingPaneView:0x608000196f40(0)]>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x600001095950 NSScrollView:0x6000001daa90.trailing == MessageView:0x6000003323e0.trailing>

Set the NSUserDefault NSConstraintBasedLayoutVisualizeMutuallyExclusiveConstraints to YES to have -[NSWindow visualizeConstraints:] automatically called when this happens.  And/or, break on objc_exception_throw to catch this in the debugger.

Steps to Reproduce:
1. Click on a problem message thread to display the messages in the conversation view.
2. Click the "..." to open previously quoted text.

Expected Results:
The previously hidden content should expand so I can see what was quoted.

Actual Results:
Nothing appears to happen. Instead, the conversation view becomes disabled and I cannot view any more messages until I quit and restart Mail.