tree c3230a07092b2679a68a9d25ae96f15cd3e77ef6
parent 0ef405b3c8c0213282ef15c48462f16d03442bac
author Edward Thomson <ethomson@edwardthomson.com> 1496957033 +0100
committer Edward Thomson <ethomson@edwardthomson.com> 1497118608 +0100

checkout: cope with untracked files in directory deletion

When deleting a directory during checkout, do not simply delete the
directory, since there may be untracked files.  Instead, go into
the iterator and examine each file.

In the original code (the code with the faulty assumption), we look to
see if there's an index entry beneath the directory that we want to
remove.   Eg, it looks to see if we have a workdir entry foo and an
index entry foo/bar.txt. If this is not the case, then the working
directory must have precious files in that directory. This part is okay.
The part that's not okay is if there is an index entry foo/bar.txt. It
just blows away the whole damned directory.

That's not cool.

Instead, by simply pushing the directory itself onto the stack and
iterating each entry, we will deal with the files one by one - whether
they're in the index (and can be force removed) or not (and are
precious).

The original code was a bad optimization, assuming that we didn't need
to git_iterator_advance_into if there was any index entry in the folder.
That's wrong - we could have optimized this iff all folder entries are
in the index.

Instead, we need to simply dig into the directory and analyze its
entries.