Re: [RFC] git rm -u

Piotr Krukowiecki <piotr.krukowiecki@gmail.com> writes:

No. This is only about "git add -u<RETURN>", not any other forms of "git add ...with or without other args...".

"git add -u<RETURN>" historically meant, and it still means, to "update the index with every change in the working tree", even when you are in a subdirectory.

Back when "git add -u" was invented, we didn't have the ":/", which lets us tell commands that take pathspecs "I want everything from the top of the working tree.". If "git add -u<RETURN>" limited its operation to the current directory, after working everywhere in the working tree, cd'ing around and ending up to be in a subdirectory somwhere deep, you had to "cd ../../.. && git add -u", which was cumbersome. If "git add -u" always meant the whole tree, limiting it to the current directory with "git add -u .<RETURN>" was easy, and that is why the default was chosen to the "whole tree".

Because we have ":/" these days, changing something that limits its action to the current directory by default to instead work on the whole tree no longer makes much sense. That is, if we _were_ to change "git add -u<RETURN>", it would be in the opposite direction, i.e. to update the index only with the paths below the current directory.

Such a change has to be done carefully. Existing users do expect the current behaviour, so we have to first _break_ their fingers and habits and train them to say "add -u :/" when they mean the whole tree operation. Silently accepting "add -u" and changing its meaning to update the index only with the paths below the current directory will cause them trouble by leaving changes they _thought_ they added out of the index, and is an unacceptable change.

The first step of migration is "git add -u<RETURN>" that loudly warns, so that uses of that form in scripts are updated before the second step to avoid a flag-day breakage and start traing fingers and habits of the users.

The second step is to make "add -u<RETURN>" fail, again with a message that tells users to be explicit and add ":/" or "." at the end if they mean "the whole tree" or "the current directory".

After keeping Git in that secnd step for sufficiently long time to train users to type ":/" or "." explicitly, we can then finally switch the default of "git add -u<RETURN>" to limit it to the current directory, instead of failing the command.