`*' gitignores and nested ignores

According to the man page, a .gitignore file that is deeper has higher precedence, and a `!' line overrides lower precedence ignores. I tried that, and it works in cases like the last "vmlinux*" example.

But it doesn't work if the lower precedence directory has a "*" pattern. If the last example from the man page is changed to:

               $ cat .gitignore
               *
               $ ls arch/foo/kernel/vm*
               arch/foo/kernel/vmlinux.lds.S
               $ echo ´!/vmlinux*´ >arch/foo/kernel/.gitignore

then -- IIUC -- the second ignore should work the same, but it doesn't. This also happens if the first pattern is "/*".

Is this a bug?

BTW, my use case is to track random stuff in a directory that has lots of junk. I wanted to do this by having a toplevel "/*" ignore and add files explicitly when I want to. But there are some directories that should be tracked, and I was trying to achieve this effect by adding a "!/*" pattern in them. Is there a more convenient (or saner) way of doing this?