"William Sprent via GitGitGadget" <gitgitgadget@xxxxxxxxx> writes:
> From: William Sprent <williams@xxxxxxxxxxx>
>
> The sparse checkout documentation states that the cone mode pattern set
> is limited to patterns that either recursively include directories or
> patterns that match all files in a directory. In the sparse checkout
> file, the former manifest in the form:
>
> /A/B/C/
>
> while the latter become a pair of patterns either in the form:
>
> /A/B/
> !/A/B/*/
>
> or in the special case of matching the toplevel files:
>
> /*
> !/*/
>
> The 'add_pattern_to_hashsets()' function contains checks which serve to
> disable cone-mode when non-cone patterns are encountered. However, these
> do not catch when the pattern list attempts to match a single file or
> directory, e.g. a pattern in the form:
>
> /A/B/C
>
> This causes sparse-checkout to exhibit unexpected behaviour when such a
> pattern is in the sparse-checkout file and cone mode is enabled.
> Concretely, with the pattern like the above, sparse-checkout, in
> non-cone mode, will only include the directory or file located at
> '/A/B/C'. However, with cone mode enabled, sparse-checkout will instead
> just manifest the toplevel files but not any file located at '/A/B/C'.
>
> Relatedly, issues occur when supplying the same kind of filter when
> partial cloning with '--filter=sparse:oid=<oid>'. 'upload-pack' will
> correctly just include the objects that match the non-cone pattern
> matching. Which means that checking out the newly cloned repo with the
> same filter, but with cone mode enabled, fails due to missing objects.
>
> To fix these issues, add a cone mode pattern check that asserts that
> every pattern is either a directory match or the pattern '/*'. Add a
> test to verify the new pattern check and modify another to reflect that
> non-directory patterns are caught earlier.
>
> Signed-off-by: William Sprent <williams@xxxxxxxxxxx>
> ---
Summoning those who worked in the area, which includes area experts,
for further comments, picked out of output from
$ git shortlog --no-merges --grep=cone --since=2.years -s -n -e
> diff --git a/dir.c b/dir.c
> index fbdb24fc819..4e99f0c868f 100644
> --- a/dir.c
> +++ b/dir.c
> @@ -732,6 +732,13 @@ static void add_pattern_to_hashsets(struct pattern_list *pl, struct path_pattern
> goto clear_hashmaps;
> }
>
> + if (!(given->flags & PATTERN_FLAG_MUSTBEDIR) &&
> + strcmp(given->pattern, "/*")) {
> + /* Not a cone pattern. */
> + warning(_("unrecognized pattern: '%s'"), given->pattern);
> + goto clear_hashmaps;
> + }
> +
> prev = given->pattern;
> cur = given->pattern + 1;
> next = given->pattern + 2;
> diff --git a/t/t1091-sparse-checkout-builtin.sh b/t/t1091-sparse-checkout-builtin.sh
> index b563d6c263e..627267be153 100755
> --- a/t/t1091-sparse-checkout-builtin.sh
> +++ b/t/t1091-sparse-checkout-builtin.sh
> @@ -238,7 +238,7 @@ test_expect_success 'cone mode: match patterns' '
> test_expect_success 'cone mode: warn on bad pattern' '
> test_when_finished mv sparse-checkout repo/.git/info/ &&
> cp repo/.git/info/sparse-checkout . &&
> - echo "!/deep/deeper/*" >>repo/.git/info/sparse-checkout &&
> + echo "!/deep/deeper/*/" >>repo/.git/info/sparse-checkout &&
> git -C repo read-tree -mu HEAD 2>err &&
> test_i18ngrep "unrecognized negative pattern" err
> '
> @@ -667,6 +667,15 @@ test_expect_success 'pattern-checks: starting "*"' '
> check_read_tree_errors repo "a deep" "disabling cone pattern matching"
> '
>
> +test_expect_success 'pattern-checks: non directory pattern' '
> + cat >repo/.git/info/sparse-checkout <<-\EOF &&
> + /deep/deeper1/a
> + EOF
> + check_read_tree_errors repo deep "disabling cone pattern matching" &&
> + check_files repo/deep deeper1 &&
> + check_files repo/deep/deeper1 a
> +'
> +
> test_expect_success 'pattern-checks: contained glob characters' '
> for c in "[a]" "\\" "?" "*"
> do
>
> base-commit: 7c2ef319c52c4997256f5807564523dfd4acdfc7
