What is the general recommendation as to what to do with the thread from a seam that has been broken?
I have this concern when I am repairing stuffed animals, which my kids have a plenty of, that get worn from general play or roughed up by real animals. The following diagram might better illustrate my issue.
In the above image the gray material represents the stuffing of the toy and the red is the existing thread from the stitching.
Normally what I do is repair over the thread a small distance to try and trap the existing thread from pulling out further. That does not always work and sometimes it comes out anyway.
Places where the seam only has thread from one end I tie my thread to the tail of the stitch and work away. I can't do that on both ends though.
I realize this questions motivation comes from small cheap toys but this would apply as well to some clothing seams as well.