index: canonicalize directory case when adding

On case insensitive systems, when given a user-provided path in the
higher-level index addition functions (eg `git_index_add_bypath` /
`git_index_add_frombuffer`), examine the index to try to match the
given path to an existing directory.

Various mechanisms can cause the on-disk representation of a folder
to not match the representation in HEAD or the index - for example,
a case changing rename of some file `a/file.txt` to `A/file.txt`
will update the paths in the index, but not rename the folder on
disk.

If a user subsequently adds `a/other.txt`, then this should be stored
in the index as `A/other.txt`.

1 files changed, 148 insertions, 0 deletions

diff --git a/tests/index/bypath.c b/tests/index/bypath.c
index b607e1732..17bba6ad5 100644
--- a/tests/index/bypath.c
+++ b/tests/index/bypath.c
@@ -72,3 +72,151 @@ void test_index_bypath__add_hidden(void)
 	cl_assert_equal_i(GIT_FILEMODE_BLOB, entry->mode);
 #endif
 }
+
+void test_index_bypath__add_honors_existing_case(void)
+{
+	const git_index_entry *entry;
+
+	if (!cl_repo_get_bool(g_repo, "core.ignorecase"))
+		clar__skip();
+
+	cl_git_mkfile("submod2/just_a_dir/file1.txt", "This is a file");
+	cl_git_mkfile("submod2/just_a_dir/file2.txt", "This is another file");
+	cl_git_mkfile("submod2/just_a_dir/file3.txt", "This is another file");
+	cl_git_mkfile("submod2/just_a_dir/file4.txt", "And another file");
+
+	cl_git_pass(git_index_add_bypath(g_idx, "just_a_dir/File1.txt"));
+	cl_git_pass(git_index_add_bypath(g_idx, "JUST_A_DIR/file2.txt"));
+	cl_git_pass(git_index_add_bypath(g_idx, "Just_A_Dir/FILE3.txt"));
+
+	cl_assert(entry = git_index_get_bypath(g_idx, "just_a_dir/File1.txt", 0));
+	cl_assert_equal_s("just_a_dir/File1.txt", entry->path);
+
+	cl_assert(entry = git_index_get_bypath(g_idx, "JUST_A_DIR/file2.txt", 0));
+	cl_assert_equal_s("just_a_dir/file2.txt", entry->path);
+
+	cl_assert(entry = git_index_get_bypath(g_idx, "Just_A_Dir/FILE3.txt", 0));
+	cl_assert_equal_s("just_a_dir/FILE3.txt", entry->path);
+
+	cl_git_rewritefile("submod2/just_a_dir/file3.txt", "Rewritten");
+	cl_git_pass(git_index_add_bypath(g_idx, "Just_A_Dir/file3.txt"));
+
+	cl_assert(entry = git_index_get_bypath(g_idx, "Just_A_Dir/file3.txt", 0));
+	cl_assert_equal_s("just_a_dir/FILE3.txt", entry->path);
+}
+
+void test_index_bypath__add_honors_existing_case_2(void)
+{
+	git_index_entry dummy = { { 0 } };
+	const git_index_entry *entry;
+
+	if (!cl_repo_get_bool(g_repo, "core.ignorecase"))
+		clar__skip();
+
+	dummy.mode = GIT_FILEMODE_BLOB;
+
+	/* note that `git_index_add` does no checking to canonical directories */
+	dummy.path = "Just_a_dir/file0.txt";
+	cl_git_pass(git_index_add(g_idx, &dummy));
+
+	dummy.path = "just_a_dir/fileA.txt";
+	cl_git_pass(git_index_add(g_idx, &dummy));
+
+	dummy.path = "Just_A_Dir/fileB.txt";
+	cl_git_pass(git_index_add(g_idx, &dummy));
+
+	dummy.path = "JUST_A_DIR/fileC.txt";
+	cl_git_pass(git_index_add(g_idx, &dummy));
+
+	dummy.path = "just_A_dir/fileD.txt";
+	cl_git_pass(git_index_add(g_idx, &dummy));
+
+	dummy.path = "JUST_a_DIR/fileE.txt";
+	cl_git_pass(git_index_add(g_idx, &dummy));
+
+	cl_git_mkfile("submod2/just_a_dir/file1.txt", "This is a file");
+	cl_git_mkfile("submod2/just_a_dir/file2.txt", "This is another file");
+	cl_git_mkfile("submod2/just_a_dir/file3.txt", "This is another file");
+	cl_git_mkfile("submod2/just_a_dir/file4.txt", "And another file");
+
+	cl_git_pass(git_index_add_bypath(g_idx, "just_a_dir/File1.txt"));
+	cl_git_pass(git_index_add_bypath(g_idx, "JUST_A_DIR/file2.txt"));
+	cl_git_pass(git_index_add_bypath(g_idx, "Just_A_Dir/FILE3.txt"));
+	cl_git_pass(git_index_add_bypath(g_idx, "JusT_A_DIR/FILE4.txt"));
+
+	cl_assert(entry = git_index_get_bypath(g_idx, "just_a_dir/File1.txt", 0));
+	cl_assert_equal_s("just_a_dir/File1.txt", entry->path);
+
+	cl_assert(entry = git_index_get_bypath(g_idx, "JUST_A_DIR/file2.txt", 0));
+	cl_assert_equal_s("JUST_A_DIR/file2.txt", entry->path);
+
+	cl_assert(entry = git_index_get_bypath(g_idx, "Just_A_Dir/FILE3.txt", 0));
+	cl_assert_equal_s("Just_A_Dir/FILE3.txt", entry->path);
+
+	cl_git_rewritefile("submod2/just_a_dir/file3.txt", "Rewritten");
+	cl_git_pass(git_index_add_bypath(g_idx, "Just_A_Dir/file3.txt"));
+
+	cl_assert(entry = git_index_get_bypath(g_idx, "Just_A_Dir/file3.txt", 0));
+	cl_assert_equal_s("Just_A_Dir/FILE3.txt", entry->path);
+}
+
+void test_index_bypath__add_honors_existing_case_3(void)
+{
+	git_index_entry dummy = { { 0 } };
+	const git_index_entry *entry;
+
+	if (!cl_repo_get_bool(g_repo, "core.ignorecase"))
+		clar__skip();
+
+	dummy.mode = GIT_FILEMODE_BLOB;
+
+	dummy.path = "just_a_dir/filea.txt";
+	cl_git_pass(git_index_add(g_idx, &dummy));
+
+	dummy.path = "Just_A_Dir/fileB.txt";
+	cl_git_pass(git_index_add(g_idx, &dummy));
+
+	dummy.path = "just_A_DIR/FILEC.txt";
+	cl_git_pass(git_index_add(g_idx, &dummy));
+
+	dummy.path = "Just_a_DIR/FileD.txt";
+	cl_git_pass(git_index_add(g_idx, &dummy));
+
+	cl_git_mkfile("submod2/JuSt_A_DiR/fILEE.txt", "This is a file");
+
+	cl_git_pass(git_index_add_bypath(g_idx, "just_a_dir/fILEE.txt"));
+
+	cl_assert(entry = git_index_get_bypath(g_idx, "JUST_A_DIR/fILEE.txt", 0));
+	cl_assert_equal_s("just_a_dir/fILEE.txt", entry->path);
+}
+
+void test_index_bypath__add_honors_existing_case_4(void)
+{
+	git_index_entry dummy = { { 0 } };
+	const git_index_entry *entry;
+
+	if (!cl_repo_get_bool(g_repo, "core.ignorecase"))
+		clar__skip();
+
+	dummy.mode = GIT_FILEMODE_BLOB;
+
+	dummy.path = "just_a_dir/a/b/c/d/e/file1.txt";
+	cl_git_pass(git_index_add(g_idx, &dummy));
+
+	dummy.path = "just_a_dir/a/B/C/D/E/file2.txt";
+	cl_git_pass(git_index_add(g_idx, &dummy));
+
+	cl_must_pass(p_mkdir("submod2/just_a_dir/a", 0777));
+	cl_must_pass(p_mkdir("submod2/just_a_dir/a/b", 0777));
+	cl_must_pass(p_mkdir("submod2/just_a_dir/a/b/z", 0777));
+	cl_must_pass(p_mkdir("submod2/just_a_dir/a/b/z/y", 0777));
+	cl_must_pass(p_mkdir("submod2/just_a_dir/a/b/z/y/x", 0777));
+
+	cl_git_mkfile("submod2/just_a_dir/a/b/z/y/x/FOO.txt", "This is a file");
+
+	cl_git_pass(git_index_add_bypath(g_idx, "just_a_dir/A/b/Z/y/X/foo.txt"));
+
+	cl_assert(entry = git_index_get_bypath(g_idx, "just_a_dir/A/b/Z/y/X/foo.txt", 0));
+	cl_assert_equal_s("just_a_dir/a/b/Z/y/X/foo.txt", entry->path);
+}
+