While working on sparse index integration for 'git rm' [1], Shaoxuan found that removed sparse directories, when reset, would no longer be sparse. This was due to how 'unpack_trees()' determined whether a traversed directory was a sparse directory or not; it would only unpack an entry as a sparse directory if it existed in the index. However, if the sparse directory was removed, it would be treated like a non-sparse directory and its contents would be individually unpacked. To avoid this unnecessary traversal and keep the results of 'reset' as sparse as possible, the decision logic for whether a directory is sparse is changed to: * If the directory is a sparse directory in the index, unpack it. * If not, is the directory inside the sparse cone? If so, do not unpack it. * If the directory is outside the sparse cone, does it have any child entries in the index? If so, do not unpack it. * Otherwise, unpack the entry as a sparse directory. In the process of updating 'reset', a separate issue was found in 'checkout' where collapsed sparse directories did not have modified contents reported file-by-file. A similar bug was found with 'status' in 2c521b0e49 (status: fix nested sparse directory diff in sparse index, 2022-03-01), and 'checkout' was corrected the same way (setting the diff flag 'recursive' to 1). Changes since V2 ================ * Adjusted 'reset hard with removed sparse dir' test in 't1092-sparse-checkout-compatibility.sh' to avoid 'git rm' log message conflicts with [1] Changes since V1 ================ * Reverted the removal of 'index_entry_exists()' to avoid breaking other in-flight series. * Renamed 'is_missing_sparse_dir()' to 'is_new_sparse_dir()'; revised comments and commit messages to clarify what that function is doing and why. * Handled "unexpected" inputs to 'is_new_sparse_dir()' more gently, returning 0 if 'p' is not a directory or the directory already exists in the index (rather than exiting with 'BUG()'). This is intended to make 'is_new_sparse_dir()' less reliant on information about the index established by 'unpack_callback()' & 'unpack_single_entry()', resulting in easier-to-read and more reusable code. Thanks! * Victoria [1] https://lore.kernel.org/git/20220803045118.1243087-1-shaoxuan.yuan02@xxxxxxxxx/ Victoria Dye (4): checkout: fix nested sparse directory diff in sparse index oneway_diff: handle removed sparse directories cache.h: create 'index_name_pos_sparse()' unpack-trees: unpack new trees as sparse directories builtin/checkout.c | 1 + cache.h | 9 ++ diff-lib.c | 5 ++ read-cache.c | 5 ++ t/t1092-sparse-checkout-compatibility.sh | 25 ++++++ unpack-trees.c | 106 ++++++++++++++++++++--- 6 files changed, 141 insertions(+), 10 deletions(-) base-commit: 4af7188bc97f70277d0f10d56d5373022b1fa385 Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1312%2Fvdye%2Freset%2Fhandle-missing-dirs-v3 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1312/vdye/reset/handle-missing-dirs-v3 Pull-Request: https://github.com/gitgitgadget/git/pull/1312 Range-diff vs v2: 1: 255318f4dc6 = 1: 255318f4dc6 checkout: fix nested sparse directory diff in sparse index 2: 55c77ba4b29 = 2: 55c77ba4b29 oneway_diff: handle removed sparse directories 3: d0bdec63286 = 3: d0bdec63286 cache.h: create 'index_name_pos_sparse()' 4: 97ca668102c ! 4: 010d5e51595 unpack-trees: unpack new trees as sparse directories @@ t/t1092-sparse-checkout-compatibility.sh: test_expect_success 'reset with wildca +test_expect_success 'reset hard with removed sparse dir' ' + init_repos && + -+ test_all_match git rm -r --sparse folder1 && ++ run_on_all git rm -r --sparse folder1 && + test_all_match git status --porcelain=v2 && + + test_all_match git reset --hard && -- gitgitgadget
