index: support index v4

Support reading and writing index v4.  Index v4 uses a very simple
compression scheme for pathnames, but is otherwise similar to index v3.

Signed-off-by: David Turner <dturner@twitter.com>

1 files changed, 41 insertions, 0 deletions

diff --git a/tests/index/version.c b/tests/index/version.c
new file mode 100644
index 000000000..3fd240d3c
--- /dev/null
+++ b/tests/index/version.c
@@ -0,0 +1,41 @@
+#include "clar_libgit2.h"
+#include "index.h"
+
+static git_repository *g_repo = NULL;
+
+void test_index_version__can_write_v4(void)
+{
+	git_index *index;
+	const git_index_entry *entry;
+
+	g_repo = cl_git_sandbox_init("filemodes");
+	cl_git_pass(git_repository_index(&index, g_repo));
+
+	cl_assert(index->on_disk);
+	cl_assert(git_index_version(index) == 2);
+
+	cl_assert(git_index_entrycount(index) == 6);
+
+	cl_git_pass(git_index_set_version(index, 4));
+
+	cl_git_pass(git_index_write(index));
+	git_index_free(index);
+
+	cl_git_pass(git_repository_index(&index, g_repo));
+	cl_assert(git_index_version(index) == 4);
+
+	entry = git_index_get_bypath(index, "exec_off", 0);
+	cl_assert(entry);
+	entry = git_index_get_bypath(index, "exec_off2on_staged", 0);
+	cl_assert(entry);
+	entry = git_index_get_bypath(index, "exec_on", 0);
+	cl_assert(entry);
+
+	git_index_free(index);
+}
+
+void test_index_version__cleanup(void)
+{
+        cl_git_sandbox_cleanup();
+        g_repo = NULL;
+}