sparse-checkout: sanitize for nested folders

If a user provides folders A/ and A/B/ for inclusion in a cone-mode
sparse-checkout file, the parsing logic will notice that A/ appears
both as a "parent" type pattern and as a "recursive" type pattern.
This is unexpected and hence will complain via a warning and revert
to the old logic for checking sparse-checkout patterns.

Prevent this from happening accidentally by sanitizing the folders
for this type of inclusion in the 'git sparse-checkout' builtin.
This happens in two ways:

1. Do not include any parent patterns that also appear as recursive
   patterns.

2. Do not include any recursive patterns deeper than other recursive
   patterns.

In order to minimize duplicate code for scanning parents, create
hashmap_contains_parent() method. It takes a strbuf buffer to
avoid reallocating a buffer when calling in a tight loop.

Helped-by: Eric Wong <e@80x24.org>
Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/sparse-checkout.c b/builtin/sparse-checkout.c
index 85cc801f03b06280e2bbe627d244d3aa79d7c927..55b337ad8e7567bb3ab838a1c90b247ad91a8aa8 100644 (file)
--- a/builtin/sparse-checkout.c
+++ b/builtin/sparse-checkout.c
@@ -81,9 +81,17 @@ static void write_cone_to_file(FILE *fp, struct pattern_list *pl)
        struct pattern_entry *pe;
        struct hashmap_iter iter;
        struct string_list sl = STRING_LIST_INIT_DUP;
+       struct strbuf parent_pattern = STRBUF_INIT;
 
-       hashmap_for_each_entry(&pl->parent_hashmap, &iter, pe, ent)
-               string_list_insert(&sl, pe->pattern);
+       hashmap_for_each_entry(&pl->parent_hashmap, &iter, pe, ent) {
+               if (hashmap_get_entry(&pl->recursive_hashmap, pe, ent, NULL))
+                       continue;
+
+               if (!hashmap_contains_parent(&pl->recursive_hashmap,
+                                            pe->pattern,
+                                            &parent_pattern))
+                       string_list_insert(&sl, pe->pattern);
+       }
 
        string_list_sort(&sl);
        string_list_remove_duplicates(&sl, 0);
@@ -99,8 +107,14 @@ static void write_cone_to_file(FILE *fp, struct pattern_list *pl)
 
        string_list_clear(&sl, 0);
 
-       hashmap_for_each_entry(&pl->recursive_hashmap, &iter, pe, ent)
-               string_list_insert(&sl, pe->pattern);
+       hashmap_for_each_entry(&pl->recursive_hashmap, &iter, pe, ent) {
+               if (!hashmap_contains_parent(&pl->recursive_hashmap,
+                                            pe->pattern,
+                                            &parent_pattern))
+                       string_list_insert(&sl, pe->pattern);
+       }
+
+       strbuf_release(&parent_pattern);
 
        string_list_sort(&sl);
        string_list_remove_duplicates(&sl, 0);

diff --git a/t/t1091-sparse-checkout-builtin.sh b/t/t1091-sparse-checkout-builtin.sh
index fbd46c3f6193106af091bc2b2dc1cbb90ffcc493..b88d08da9890d6569d0cafac62091e58868616de 100755 (executable)
--- a/t/t1091-sparse-checkout-builtin.sh
+++ b/t/t1091-sparse-checkout-builtin.sh
@@ -237,4 +237,15 @@ test_expect_success 'cone mode: init and set' '
        test_cmp expect dir
 '
 
+test_expect_success 'cone mode: set with nested folders' '
+       git -C repo sparse-checkout set deep deep/deeper1/deepest 2>err &&
+       test_line_count = 0 err &&
+       cat >expect <<-EOF &&
+               /*
+               !/*/
+               /deep/
+       EOF
+       test_cmp repo/.git/info/sparse-checkout expect
+'
+
 test_done