From 358962102ab7db883868078e85705278f2f55fd5 Mon Sep 17 00:00:00 2001 From: Derrick Stolee Date: Fri, 3 Dec 2021 21:05:11 -0500 Subject: [PATCH 1/2] t1092: add deeper changes during a checkout Extend the repository data in the setup of t1092 to include more directories within two parent directories. This reproduces a bug found by users of the sparse index feature with suitably-complicated sparse-checkout definitions. Add a failing test that fails in its first 'git checkout deepest' run in the sparse index case with this error: error: Your local changes to the following files would be overwritten by checkout: deep/deeper1/deepest2/a deep/deeper1/deepest3/a Please commit your changes or stash them before you switch branches. Aborting The next change will fix this error, and that fix will make it clear why the extra depth is necessary for revealing this bug. The assignment of the sparse-checkout definition to include deep/deeper1/deepest as a sibling directory is important to ensure that deep/deeper1 is not a sparse directory entry, but deep/deeper1/deepest2 is. Signed-off-by: Derrick Stolee --- t/t1092-sparse-checkout-compatibility.sh | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh index c4cfb0869586f9..0697aca6f359e4 100755 --- a/t/t1092-sparse-checkout-compatibility.sh +++ b/t/t1092-sparse-checkout-compatibility.sh @@ -19,6 +19,8 @@ test_expect_success 'setup' ' mkdir folder1 folder2 deep x && mkdir deep/deeper1 deep/deeper2 deep/before deep/later && mkdir deep/deeper1/deepest && + mkdir deep/deeper1/deepest2 && + mkdir deep/deeper1/deepest3 && echo "after deeper1" >deep/e && echo "after deepest" >deep/deeper1/e && cp a folder1 && @@ -30,7 +32,9 @@ test_expect_success 'setup' ' cp a deep/deeper2 && cp a deep/later && cp a deep/deeper1/deepest && - cp -r deep/deeper1/deepest deep/deeper2 && + cp a deep/deeper1/deepest2 && + cp a deep/deeper1/deepest3 && + cp -r deep/deeper1/ deep/deeper2 && mkdir deep/deeper1/0 && mkdir deep/deeper1/0/0 && touch deep/deeper1/0/1 && @@ -126,6 +130,8 @@ test_expect_success 'setup' ' git checkout -b deepest base && echo "updated deepest" >deep/deeper1/deepest/a && + echo "updated deepest2" >deep/deeper1/deepest2/a && + echo "updated deepest3" >deep/deeper1/deepest3/a && git commit -a -m "update deepest" && git checkout -f base && @@ -302,6 +308,14 @@ test_expect_success 'add, commit, checkout' ' test_all_match git checkout - ' +test_expect_failure 'deep changes during checkout' ' + init_repos && + + test_sparse_match git sparse-checkout set deep/deeper1/deepest && + test_all_match git checkout deepest && + test_all_match git checkout base +' + test_expect_success 'add outside sparse cone' ' init_repos && From cb146c4d36d24b2e63844345fb037885afece34d Mon Sep 17 00:00:00 2001 From: Derrick Stolee Date: Fri, 3 Dec 2021 18:57:43 -0500 Subject: [PATCH 2/2] unpack-trees: use traverse_path instead of name The sparse_dir_matches_path() method compares a cache entry that is a sparse directory entry against a 'struct traverse_info *info' and a 'struct name_entry *p' to see if the cache entry has exactly the right name for those other inputs. This method was introduced in 523506d (unpack-trees: unpack sparse directory entries, 2021-07-14), but included a significant mistake. The path comparisons used 'info->name' instead of 'info->traverse_path'. Since 'info->name' only stores a single tree entry name while 'info->traverse_path' stores the full path from root, this method does not work when 'info' is in a subdirectory of a directory. Replacing the right strings and their corresponding lengths make the method work properly. The previous change included a failing test that exposes this issue. That test now passes. The critical detail is that as we go deep into unpack_trees(), the logic for merging a sparse directory entry with a tree entry during 'git checkout' relies on this sparse_dir_matches_path() in order to avoid calling traverse_trees_recursive() during unpack_callback() in this hunk: if (!is_sparse_directory_entry(src[0], names, info) && traverse_trees_recursive(n, dirmask, mask & ~dirmask, names, info) < 0) { return -1; } For deep paths, the short-circuit never occurred and traverse_trees_recursive() was being called incorrectly and that was causing other strange issues. Specifically, the error message from the now-passing test previously included this: error: Your local changes to the following files would be overwritten by checkout: deep/deeper1/deepest2/a deep/deeper1/deepest3/a Please commit your changes or stash them before you switch branches. Aborting These messages occurred because the 'current' cache entry in twoway_merge() was showing as NULL because the index did not contain entries for the paths contained within the sparse directory entries. We instead had 'oldtree' given as the entry at HEAD and 'newtree' as the entry in the target tree. This led to reject_merge() listing these paths. Now that sparse_dir_matches_path() works the same for deep paths as it does for shallow depths, the rest of the logic kicks in to properly handle modifying the sparse directory entries as designed. Reported-by: Gustave Granroth Reported-by: Mike Marcelais Signed-off-by: Derrick Stolee --- t/t1092-sparse-checkout-compatibility.sh | 2 +- unpack-trees.c | 14 ++++++++------ 2 files changed, 9 insertions(+), 7 deletions(-) diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh index 0697aca6f359e4..f67992a7249e6b 100755 --- a/t/t1092-sparse-checkout-compatibility.sh +++ b/t/t1092-sparse-checkout-compatibility.sh @@ -308,7 +308,7 @@ test_expect_success 'add, commit, checkout' ' test_all_match git checkout - ' -test_expect_failure 'deep changes during checkout' ' +test_expect_success 'deep changes during checkout' ' init_repos && test_sparse_match git sparse-checkout set deep/deeper1/deepest && diff --git a/unpack-trees.c b/unpack-trees.c index 7229a4a820de5c..5ce4f8d8cc71c3 100644 --- a/unpack-trees.c +++ b/unpack-trees.c @@ -1258,7 +1258,9 @@ static int find_cache_pos(struct traverse_info *info, /* * Given a sparse directory entry 'ce', compare ce->name to - * info->name + '/' + p->path + '/' if info->name is non-empty. + * info->traverse_path + p->path + '/' if info->traverse_path + * is non-empty. + * * Compare ce->name to p->path + '/' otherwise. Note that * ce->name must end in a trailing '/' because it is a sparse * directory entry. @@ -1270,11 +1272,11 @@ static int sparse_dir_matches_path(const struct cache_entry *ce, assert(S_ISSPARSEDIR(ce->ce_mode)); assert(ce->name[ce->ce_namelen - 1] == '/'); - if (info->namelen) - return ce->ce_namelen == info->namelen + p->pathlen + 2 && - ce->name[info->namelen] == '/' && - !strncmp(ce->name, info->name, info->namelen) && - !strncmp(ce->name + info->namelen + 1, p->path, p->pathlen); + if (info->pathlen) + return ce->ce_namelen == info->pathlen + p->pathlen + 1 && + ce->name[info->pathlen - 1] == '/' && + !strncmp(ce->name, info->traverse_path, info->pathlen) && + !strncmp(ce->name + info->pathlen, p->path, p->pathlen); return ce->ce_namelen == p->pathlen + 1 && !strncmp(ce->name, p->path, p->pathlen); }