From: Jens Lehmann Date: Thu, 11 Sep 2014 19:37:45 GMT Subject: Re: [PATCH v3 4/8] combine-diff: do not pass revs->dense_combined_merges redundantly Message-ID: <5411FA09.3050303@web.de> In-Reply-To: Am 08.09.2014 um 19:29 schrieb Junio C Hamano: > Thomas Rast writes: > >> The existing code passed revs->dense_combined_merges along revs itself >> into the combine-diff functions, which is rather redundant. Remove >> the 'dense' argument until much further down the callchain to simplify >> callers. > > It was not apparent that the changes to diff_tree_combined_merge() > was correct without looking at both of its callsites, but one passes > the .dense_combined_merges member, and the other in submodules > always gives true, which you covered here: > >> Note that while the caller in submodule.c needs to do extra work now, >> the next commit will simplify this to a single setting again. > >> diff --git a/submodule.c b/submodule.c >> index c3a61e7..0499de6 100644 >> --- a/submodule.c >> +++ b/submodule.c >> @@ -482,10 +482,13 @@ static void find_unpushed_submodule_commits(struct commit *commit, >> struct rev_info rev; >> >> init_revisions(&rev, NULL); >> + rev.ignore_merges = 0; >> + rev.combined_merges = 1; >> + rev.dense_combined_merges = 1; >> rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK; >> rev.diffopt.format_callback = collect_submodules_from_diff; >> rev.diffopt.format_callback_data = needs_pushing; >> - diff_tree_combined_merge(commit, 1, &rev); >> + diff_tree_combined_merge(commit, &rev); >> } > > I briefly wondered if there can be any unwanted side effects in this > particular codepath that is caused by setting rev.combined_merges > which was not set in the original code, but seeing that this &rev is > not used for anything other than diff_tree_combined_merge(), it > should be OK. > > Also I wondered if this is leaking whatever in the &rev structure, > but in this call I think rev is used only for its embedded diffopt > in a way that does not leak anything, so it seems to be OK, but I'd > appreciate if submodule folks can double check. The only thing the collect_submodules_from_diff() callback does is to collect the to-be-pushed submodules in the needs_pushing string_list initialized with STRING_LIST_INIT_DUP which is cleared at the end of push_unpushed_submodules(), so I think we should be ok here.