On 21 May 2011, at 03:38, Sidney San Martín wrote:
I noticed that a file I was working on was suddenly four times its original length — its content had been quadruplicated! I also noticed that whatever I changed in the first copy affected the others, even after I emptied out the file and started typing fresh.
This could have been after inserting a snippet with mirrors, doing column typing, or appending to each line in selection.
It generally shouldn’t be stuck in that mode, hard to say how it happened, but I believe there exists a few ways to fool TextMate into staying in the mirroring mode.