Before I continue rooting around in the source, though, I wonder if the real issue here isn't the fact that add -p fails to support new files (requiring the intent-to-add workaround in the first place). I have always thought it's a confusing user experience that git add -p on a file that isn't yet tracked simply returns "No changes". The underlying problem may be, and I say this without intimate knowledge of the subsystem, that we're now trying to force add-patch.c to do something it doesn't actually support, namely new files, whereas before it was attempting to patch what it saw as an empty file. This (patch-adding new files) is real in my workflow; is there any reason why git add -p with an explicit argument shouldn't attempt to add untracked files covered by the explicit argument? (In addition to fixing it for intent-to-adds.)
