Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx> writes: > In the preceding [1] (pack-objects: move revs out of > get_object_list(), 2022-03-22) the "repo_init_revisions()" was moved > to cmd_pack_objects() so that it unconditionally took place for all > invocations of "git pack-objects". > > We'd thus start leaking memory, which is easily reproduced in > e.g. git.git by feeding e83c5163316 (Initial revision of "git", the > information manager from hell, 2005-04-07) to "git pack-objects"; > ... > Narrowly fixing that commit would have been easy, just add call > repo_init_revisions() right before get_object_list(), which is > effectively what was done before that commit. > > But an unstated constraint when setting it up early is that it was > needed for the subsequent [2] (pack-objects: parse --filter directly > into revs.filter, 2022-03-22), i.e. we might have a --filter > command-line option, and need to either have the "struct rev_info" > setup when we encounter that option, or later. > > Let's just change the control flow so that we'll instead set up the > "struct rev_info" only when we need it. Doing so leads to a bit more > verbosity, but it's a lot clearer what we're doing and why. Is this about "we take it as given that the use of rev_info leaks until we fix revisions API, so let's keep its use limited to avoid unnecessary leaks"? If so, it sort-of makes sense, but smells like a roundabout way to address the issue. An obvious alternative is to wait until both the topic and the "plug revision API" topic graduate and then add a "release" call to release the resource in the same sope as the unconditional call to init_revisions at the end. I do not quite get what on-demand lazy set-up buys us. What we need to lazily set-up, when we do lazily set-up, needs to be released either way, no?
