When this developer finally went to commit his/her changes, they had also reformatted most of the codebase into his/her preferred coding style/format. This was even for files for which no other changes had been made!Imagine the next developer coming along and pulling down the latest changes from the source control system and trying to merge them into their own local changes.
Because of all these code-format-only changes, it became nearly impossible to merge any changes without going through every conflicted file and painstakingly reconcile the changes.
I’ve seen this happen on a few projects where there have been sequential single developers some of which reformatted the whole code base within a few days of taking over.
It made it impossible to perform a “blame” or proper history tracking of feature changes.
That increased the cost of maintenance a lot.
I’ve been on several teams that enforced a pre-checkin standardised formatting of the code. Only rarely that causes problems, usually it’s a blessing to as it makes for a consistent formatting of the code-base where it is much easier to cut the crap and focus on what the real problem is.
–jeroen
Source: The Oracle at Delphi: Code is the language, formatting is the dialect.