Comment 143 for bug 272247

Nitto,

I don't know how easy it is to move between versions, but you may prefer using an algorithm like this:

Starting with revisions from 1 to 90 to check,

startrevision=1
finalrevision=90
while startrevision < finalrevision
    If revision startrevision don't has the bug
        If revision finalrevision has the bug
            middle=(startrevision+finalrevision)/2
            if revision middle has the bug
                startrevision=middle+1
                finalrevision=finalrevision-1
            else (middle don't has the bug)
                startrevision=startrevision+1
                finalrevision=middle-1

It's commonly used in programming, but also very easily applicable in real life. It will help you find quickier with what revision the problem started. Oh, my description of the algorithm should have some bugs, but I'm trusting that you're human and will not get into an infinite loop :P

Just to make it clearer: divide the area of your search by two, check if the middle element of it has the bug, if it has it, it should have started in the first half, if not, it should have started in the second half. Then, repeat the procedure.