Junio C Hamano <gitster@xxxxxxxxx> 于2021年5月11日周二 上午10:29写道： > > "ZheNing Hu via GitGitGadget" <gitgitgadget@xxxxxxxxx> writes: > > > Change from last version: > > Prove that the bug may appear when using %(color) atom. And add > > corresponding test for it. > > > ++test_expect_success '%(color:#aa22ac) must success' ' > > s/success/succeed/ > > But more importantly, I am not sure how this is supposed to > demonstrate existing breakage around the %(push). Did you mean to > use %(push) instead of %(refname) or something? > Ah, I don’t think this scene of damage is related to using %(push) or %(refname). We are just in the process of using `populate_value()`, if the atom we specify meets the following conditions, then the condition of atom->u.remote_ref.push!=0 will be established. 1. The atom that triggers the bug , its "if" condition order must after "if (atom->u.remote_ref.push)", such as %(refname) or %(worktreepath), they can be executed correctly because their order is before "push". 2. The member size in used_atom.u corresponding to the atom must larger than 17 bytes, because the offset of "u.remote_ref.push" in "u.remote_ref" is 17, the satisfied atoms are only "%(color)" and "%(contents)", their corresponding members are u.color and u.contents. 3. We happen to be able to fill in the 17th position of these structures, which makes atom->u.remote_ref.push not equal to 0 established. So this kind of bug is not related to %(push), an atom that satisfies the above conditions will make `if (atom->u.remote_ref.push)` be true. then execute the program logic related to `%(push)`. Now, we only have `%(color)` can trigger it "sometime", It is unpredictable to fill in the 17th byte of used_atom.u.color, so we cannot track all the atoms related to this bug. git for-each-ref --format="%(color:#aa22ac)%(refname)" git for-each-ref --format="%(color:#aa22ad)%(refname)" will trigger the bug. git for-each-ref --format="%(color:#aa22ae)%(refname)" git for-each-ref --format="%(color:#aa22af)%(refname)" will not trigger the bug. In other words, we cannot use a perfect test set to cover all broken. So now `%(color:#aa22ac)` is enough for explain the problem of this bug. Thanks. -- ZheNing Hu
