I personally turn invisible characters on so mistakes like that are a bit harder to make. Along that line of thinking, the code should probably be reviewed by

I personally turn invisible characters on so mistakes like that are a bit harder to make. Along that line of thinking, the code should probably be reviewed by at least one other person before being officially committed, so one would hope that would be the place to find and fix such errors. Personally I've always felt the benefit of letting everyone set their own indentation level far outweighs the off chance of someone misindenting code (and I've never seen it cause a problem so far, not that it means much).