On Tue, Mar 12, 2019 at 05:39:13PM +0000, Ramsay Jones wrote: > On 12/03/2019 16:55, Ramsay Jones wrote: > > From: Jeff King <p...@peff.net> > > > > Signed-off-by: Ramsay Jones <ram...@ramsayjones.plus.com>
Could definitely use a commit message. I think it's something like: We use the "offset" variable for two purposes. It's the offset into the packfile that the caller provides us (which is rightly an off_t, since we might have a packfile much larger than memory). But later we also use it as the offset within a given mmap'd window, and that window cannot be larger than a size_t. For the second use, the fact that we have an off_t leads to some confusion when we assign it to the "left" variable, is a size_t. It is in fact correct (because our earlier "offset -= win->offset" means we must be within the pack window), but using a separate variable of the right type makes that much more obvious. You'll note that I snuck in the assumption that "left" is a size_t, which as you noted is not quite valid yet. :) > Heh, of course I should have tried applying on top of today's > codebase before sending it out! :( > > Having just done so, it quickly showed that this patch assumes > that the 'left' parameter to use_pack() has been changed from > an 'unsigned long *' to an 'size_t *' as part of the series > that was being discussed in the above link. Yep. Until then, I do not think there is much point (and in fact I'd suspect this code behaves incorrectly on Windows, where "unsigned long" is too short; hopefully they clamp pack windows to 4GB by default there, which would work around it). But I would be very happy if you wanted to resurrect the "left" patch and then do this on top. :) -Peff
