On Tue, 2016-11-15 at 12:40 -0500, Jeff King wrote: > On Tue, Nov 15, 2016 at 12:33:04PM -0500, Matt McCutchen wrote: > > > > > On Tue, 2016-11-15 at 12:06 -0500, Jeff King wrote: > > > > > > - when an object write is optimized out because we already have the > > > object, git will update the mtime on the file (loose object or > > > packfile) to freshen it > > > > FWIW, I am not seeing this happen when I do "git read-tree --prefix" > > followed by "git write-tree" using the current master (3ab2281). See > > the attached test script. > > The optimization I'm thinking about is the one from write_sha1_file(), > which learned to freshen in 33d4221c7 (write_sha1_file: freshen existing > objects, 2014-10-15). > > I suspect the issue is that read-tree populates the cache-tree index > extension, and then write-tree omits the object write before it even > gets to write_sha1_file(). The solution is that it should probably be > calling one of the freshen() functions (possibly just replacing > has_sha1_file() with check_and_freshen(), but I haven't looked). > > I'd definitely welcome patches in this area. Cool, it's nice to have an idea of what's going on. I don't think I'm going to try to fix it myself though. By the way, thanks for the fast response to my original question! Matt