[MlMt] r5070 - UI issue with text entry (compose)

[Scott A. McIntyre]

Hi,

I've actually noticed this for a few versions now, but, in r5070 it 
seems worse.

In earlier versions, if I were to reply to a message and paste a block 
(say, 20-30 lines) of text at the top (I hate top-quoting, but, let's 
worry about that problem later), the rest of the text in the compose 
window would be VERY slow to update, indeed, during the initial paste a 
few lines would disappear for half a second during a re-draw.

With the current alpha build, any amount of text entry at the top of a 
message seems to create a very slow UI update for the rest of the text 
being pushed downwards.

This is on a pretty well spec'd 64GB RAM laden new MacPro, so, confident 
the issue isn't my local hardware...

Cheers,

Scott