checkout: remove files before writing new ones

On case insensitive filesystems, we may have files in the working
directory that case fold to a name we want to write.  Remove those
files (by default) so that we will not end up with a filename that
has the unexpected case.

2 files changed, 99 insertions, 2 deletions

diff --git a/tests/checkout/icase.c b/tests/checkout/icase.c
new file mode 100644
index 000000000..625f19627
--- /dev/null
+++ b/tests/checkout/icase.c
@@ -0,0 +1,97 @@
+#include "clar_libgit2.h"
+
+#include "git2/checkout.h"
+#include "path.h"
+
+static git_repository *repo;
+static git_object *obj;
+static git_checkout_options checkout_opts;
+
+void test_checkout_icase__initialize(void)
+{
+	git_oid id;
+
+	repo = cl_git_sandbox_init("testrepo");
+
+	cl_git_pass(git_reference_name_to_id(&id, repo, "refs/heads/dir"));
+	cl_git_pass(git_object_lookup(&obj, repo, &id, GIT_OBJ_ANY));
+
+	git_checkout_init_options(&checkout_opts, GIT_CHECKOUT_OPTIONS_VERSION);
+	checkout_opts.checkout_strategy = GIT_CHECKOUT_FORCE;
+}
+
+void test_checkout_icase__cleanup(void)
+{
+	git_object_free(obj);
+	cl_git_sandbox_cleanup();
+}
+
+static void assert_name_is(const char *expected)
+{
+	char *actual;
+	size_t actual_len, expected_len, start;
+
+	cl_assert(actual = realpath(expected, NULL));
+
+	expected_len = strlen(expected);
+	actual_len = strlen(actual);
+	cl_assert(actual_len >= expected_len);
+
+	start = actual_len - expected_len;
+	cl_assert_equal_s(expected, actual + start);
+
+	if (start)
+		cl_assert_equal_strn("/", actual + (start - 1), 1);
+
+	free(actual);
+}
+
+void test_checkout_icase__overwrites_files_for_files(void)
+{
+	cl_git_write2file("testrepo/NEW.txt", "neue file\n", 10, \
+		O_WRONLY | O_CREAT | O_TRUNC, 0644);
+
+	cl_git_pass(git_checkout_tree(repo, obj, &checkout_opts));
+	assert_name_is("testrepo/new.txt");
+}
+
+void test_checkout_icase__overwrites_links_for_files(void)
+{
+	cl_must_pass(p_symlink("../tmp", "testrepo/NEW.txt"));
+
+	cl_git_pass(git_checkout_tree(repo, obj, &checkout_opts));
+
+	cl_assert(!git_path_exists("tmp"));
+	assert_name_is("testrepo/new.txt");
+}
+
+void test_checkout_icase__overwites_folders_for_files(void)
+{
+	cl_must_pass(p_mkdir("testrepo/NEW.txt", 0777));
+
+	cl_git_pass(git_checkout_tree(repo, obj, &checkout_opts));
+
+	assert_name_is("testrepo/new.txt");
+	cl_assert(!git_path_isdir("testrepo/new.txt"));
+}
+
+void test_checkout_icase__overwrites_files_for_folders(void)
+{
+	cl_git_write2file("testrepo/A", "neue file\n", 10, \
+		O_WRONLY | O_CREAT | O_TRUNC, 0644);
+
+	cl_git_pass(git_checkout_tree(repo, obj, &checkout_opts));
+	assert_name_is("testrepo/a");
+	cl_assert(git_path_isdir("testrepo/a"));
+}
+
+void test_checkout_icase__overwrites_links_for_folders(void)
+{
+	cl_must_pass(p_symlink("..", "testrepo/A"));
+
+	cl_git_pass(git_checkout_tree(repo, obj, &checkout_opts));
+
+	cl_assert(!git_path_exists("b.txt"));
+	assert_name_is("testrepo/a");
+}
+
diff --git a/tests/checkout/index.c b/tests/checkout/index.c
index f94556214..112324a04 100644
--- a/tests/checkout/index.c
+++ b/tests/checkout/index.c
@@ -279,10 +279,10 @@ void test_checkout_index__options_open_flags(void)
 
 	cl_git_mkfile("./testrepo/new.txt", "hi\n");
 
-	opts.checkout_strategy = GIT_CHECKOUT_SAFE_CREATE;
+	opts.checkout_strategy =
+		GIT_CHECKOUT_FORCE | GIT_CHECKOUT_DONT_REMOVE_EXISTING;
 	opts.file_open_flags = O_CREAT | O_RDWR | O_APPEND;
 
-	opts.checkout_strategy = GIT_CHECKOUT_FORCE;
 	cl_git_pass(git_checkout_index(g_repo, NULL, &opts));
 
 	check_file_contents("./testrepo/new.txt", "hi\nmy new file\n");