diff --git a/CMakeLists.txt b/CMakeLists.txt
index 354ae3e..4783e3e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -468,9 +468,6 @@
 	SET(CMAKE_SHARED_LINKER_FLAGS_MINSIZEREL "${CMAKE_EXE_LINKER_FLAGS_MINSIZEREL}")
 
 	SET(WIN_RC "src/win32/git2.rc")
-
-   # Precompiled headers
-
 ELSE ()
 	SET(CMAKE_C_FLAGS "-D_GNU_SOURCE ${CMAKE_C_FLAGS}")
 
@@ -481,9 +478,7 @@
 		SET(CMAKE_C_FLAGS "-std=c99 -D_POSIX_C_SOURCE=200112L -D__EXTENSIONS__ -D_POSIX_PTHREAD_SEMANTICS ${CMAKE_C_FLAGS}")
 	ENDIF()
 
-	IF (WIN32 AND NOT CYGWIN)
-		SET(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -D_DEBUG")
-	ENDIF ()
+	SET(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -D_DEBUG -O0")
 
 	IF (MINGW OR MSYS) # MinGW and MSYS always do PIC and complain if we tell them to
 		STRING(REGEX REPLACE "-fPIC" "" CMAKE_SHARED_LIBRARY_C_FLAGS "${CMAKE_SHARED_LIBRARY_C_FLAGS}")
diff --git a/tests/core/structinit.c b/tests/core/structinit.c
index e9f7b4a..2d21440 100644
--- a/tests/core/structinit.c
+++ b/tests/core/structinit.c
@@ -165,4 +165,9 @@
 	CHECK_MACRO_FUNC_INIT_EQUAL( \
 		git_submodule_update_options, GIT_SUBMODULE_UPDATE_OPTIONS_VERSION, \
 		GIT_SUBMODULE_UPDATE_OPTIONS_INIT, git_submodule_update_init_options);
+
+	/* submodule update */
+	CHECK_MACRO_FUNC_INIT_EQUAL( \
+		git_proxy_options, GIT_PROXY_OPTIONS_VERSION, \
+		GIT_PROXY_OPTIONS_INIT, git_proxy_init_options);
 }
diff --git a/tests/network/remote/local.c b/tests/network/remote/local.c
index 7bae038..76872e5 100644
--- a/tests/network/remote/local.c
+++ b/tests/network/remote/local.c
@@ -2,6 +2,7 @@
 #include "buffer.h"
 #include "path.h"
 #include "posix.h"
+#include "git2/sys/repository.h"
 
 static git_repository *repo;
 static git_buf file_path_buf = GIT_BUF_INIT;
diff --git a/tests/odb/backend/backend_helpers.c b/tests/odb/backend/backend_helpers.c
index 2653702..37a8fd2 100644
--- a/tests/odb/backend/backend_helpers.c
+++ b/tests/odb/backend/backend_helpers.c
@@ -4,7 +4,7 @@
 
 static int search_object(const fake_object **out, fake_backend *fake, const git_oid *oid, size_t len)
 {
-	const fake_object *obj = fake->objects;
+	const fake_object *obj = fake->objects, *found = NULL;
 
 	while (obj && obj->oid) {
 		git_oid current_oid;
@@ -12,15 +12,18 @@
 		git_oid_fromstr(&current_oid, obj->oid);
 
 		if (git_oid_ncmp(&current_oid, oid, len) == 0) {
-			if (out)
-				*out = obj;
-			return 0;
+			if (found)
+				return GIT_EAMBIGUOUS;
+			found = obj;
 		}
 
 		obj++;
 	}
 
-	return GIT_ENOTFOUND;
+	if (found && out)
+		*out = found;
+
+	return found ? GIT_OK : GIT_ENOTFOUND;
 }
 
 static int fake_backend__exists(git_odb_backend *backend, const git_oid *oid)
@@ -31,7 +34,27 @@
 
 	fake->exists_calls++;
 
-	return search_object(NULL, fake, oid, GIT_OID_RAWSZ) == GIT_OK;
+	return search_object(NULL, fake, oid, GIT_OID_HEXSZ) == GIT_OK;
+}
+
+static int fake_backend__exists_prefix(
+	git_oid *out, git_odb_backend *backend, const git_oid *oid, size_t len)
+{
+	const fake_object *obj;
+	fake_backend *fake;
+	int error;
+
+	fake = (fake_backend *)backend;
+
+	fake->exists_prefix_calls++;
+
+	if ((error = search_object(&obj, fake, oid, len)) < 0)
+		return error;
+
+	if (out)
+		git_oid_fromstr(out, obj->oid);
+
+	return 0;
 }
 
 static int fake_backend__read(
@@ -40,19 +63,20 @@
 {
 	const fake_object *obj;
 	fake_backend *fake;
+	int error;
 
 	fake = (fake_backend *)backend;
 
 	fake->read_calls++;
 
-	if (search_object(&obj, fake, oid, GIT_OID_RAWSZ) == 0) {
-		*len_p = strlen(obj->content);
-		*buffer_p = git__strdup(obj->content);
-		*type_p = GIT_OBJ_BLOB;
-		return 0;
-	}
+	if ((error = search_object(&obj, fake, oid, GIT_OID_HEXSZ)) < 0)
+		return error;
 
-	return GIT_ENOTFOUND;
+	*len_p = strlen(obj->content);
+	*buffer_p = git__strdup(obj->content);
+	*type_p = GIT_OBJ_BLOB;
+
+	return 0;
 }
 
 static int fake_backend__read_header(
@@ -61,18 +85,19 @@
 {
 	const fake_object *obj;
 	fake_backend *fake;
+	int error;
 
 	fake = (fake_backend *)backend;
 
 	fake->read_header_calls++;
 
-	if (search_object(&obj, fake, oid, GIT_OID_RAWSZ) == 0) {
-		*len_p = strlen(obj->content);
-		*type_p = GIT_OBJ_BLOB;
-		return 0;
-	}
+	if ((error = search_object(&obj, fake, oid, GIT_OID_HEXSZ)) < 0)
+		return error;
 
-	return GIT_ENOTFOUND;
+	*len_p = strlen(obj->content);
+	*type_p = GIT_OBJ_BLOB;
+
+	return 0;
 }
 
 static int fake_backend__read_prefix(
@@ -81,20 +106,21 @@
 {
 	const fake_object *obj;
 	fake_backend *fake;
+	int error;
 
 	fake = (fake_backend *)backend;
 
 	fake->read_prefix_calls++;
 
-	if (search_object(&obj, fake, short_oid, len) == 0) {
-		git_oid_fromstr(out_oid, obj->oid);
-		*len_p = strlen(obj->content);
-		*buffer_p = git__strdup(obj->content);
-		*type_p = GIT_OBJ_BLOB;
-		return 0;
-	}
+	if ((error = search_object(&obj, fake, short_oid, len)) < 0)
+		return error;
 
-	return GIT_ENOTFOUND;
+	git_oid_fromstr(out_oid, obj->oid);
+	*len_p = strlen(obj->content);
+	*buffer_p = git__strdup(obj->content);
+	*type_p = GIT_OBJ_BLOB;
+
+	return 0;
 }
 
 static void fake_backend__free(git_odb_backend *_backend)
@@ -124,6 +150,7 @@
 	backend->parent.read_prefix = fake_backend__read_prefix;
 	backend->parent.read_header = fake_backend__read_header;
 	backend->parent.exists = fake_backend__exists;
+	backend->parent.exists_prefix = fake_backend__exists_prefix;
 	backend->parent.free = &fake_backend__free;
 
 	*out = (git_odb_backend *)backend;
diff --git a/tests/odb/backend/backend_helpers.h b/tests/odb/backend/backend_helpers.h
index 6cc1ce9..5c393c0 100644
--- a/tests/odb/backend/backend_helpers.h
+++ b/tests/odb/backend/backend_helpers.h
@@ -9,6 +9,7 @@
 	git_odb_backend parent;
 
 	int exists_calls;
+	int exists_prefix_calls;
 	int read_calls;
 	int read_header_calls;
 	int read_prefix_calls;
diff --git a/tests/odb/backend/simple.c b/tests/odb/backend/simple.c
new file mode 100644
index 0000000..c0fcd40
--- /dev/null
+++ b/tests/odb/backend/simple.c
@@ -0,0 +1,232 @@
+#include "clar_libgit2.h"
+#include "repository.h"
+#include "backend_helpers.h"
+
+#define EMPTY_HASH "e69de29bb2d1d6434b8b29ae775ad8c2e48c5391"
+
+static git_repository *_repo;
+static git_odb *_odb;
+static git_odb_object *_obj;
+static git_oid _oid;
+
+static void setup_backend(const fake_object *objs)
+{
+	git_odb_backend *backend;
+
+	cl_git_pass(build_fake_backend(&backend, objs));
+
+	cl_git_pass(git_repository_odb__weakptr(&_odb, _repo));
+	cl_git_pass(git_odb_add_backend(_odb, backend, 10));
+}
+
+static void assert_object_contains(git_odb_object *obj, const char *expected)
+{
+	const char *actual = (const char *) git_odb_object_data(obj);
+
+	cl_assert_equal_s(actual, expected);
+}
+
+void test_odb_backend_simple__initialize(void)
+{
+	_repo = cl_git_sandbox_init("testrepo.git");
+	_odb = NULL;
+	_obj = NULL;
+}
+
+void test_odb_backend_simple__cleanup(void)
+{
+	git_odb_object_free(_obj);
+	cl_git_sandbox_cleanup();
+	cl_git_pass(git_libgit2_opts(GIT_OPT_ENABLE_STRICT_HASH_VERIFICATION, 1));
+}
+
+void test_odb_backend_simple__read_of_object_succeeds(void)
+{
+	const fake_object objs[] = {
+		{ "f6ea0495187600e7b2288c8ac19c5886383a4632", "foobar" },
+		{ NULL, NULL }
+	};
+
+	setup_backend(objs);
+
+	cl_git_pass(git_oid_fromstr(&_oid, objs[0].oid));
+	cl_git_pass(git_odb_read(&_obj, _odb, &_oid));
+
+	assert_object_contains(_obj, objs[0].content);
+}
+
+void test_odb_backend_simple__read_of_nonexisting_object_fails(void)
+{
+	const fake_object objs[] = {
+		{ "f6ea0495187600e7b2288c8ac19c5886383a4632", "foobar" },
+		{ NULL, NULL }
+	};
+
+	setup_backend(objs);
+
+	cl_git_pass(git_oid_fromstr(&_oid, "f6ea0495187600e7b2288c8ac19c5886383a4633"));
+	cl_git_fail_with(GIT_ENOTFOUND, git_odb_read(&_obj, _odb, &_oid));
+}
+
+void test_odb_backend_simple__read_with_hash_mismatch_fails(void)
+{
+	const fake_object objs[] = {
+		{ "1234567890123456789012345678901234567890", "nonmatching content" },
+		{ NULL, NULL }
+	};
+
+	setup_backend(objs);
+
+	cl_git_pass(git_oid_fromstr(&_oid, objs[0].oid));
+	cl_git_fail_with(GIT_EMISMATCH, git_odb_read(&_obj, _odb, &_oid));
+}
+
+void test_odb_backend_simple__read_with_hash_mismatch_succeeds_without_verification(void)
+{
+	const fake_object objs[] = {
+		{ "1234567890123456789012345678901234567890", "nonmatching content" },
+		{ NULL, NULL }
+	};
+
+	setup_backend(objs);
+	cl_git_pass(git_oid_fromstr(&_oid, objs[0].oid));
+
+	cl_git_pass(git_libgit2_opts(GIT_OPT_ENABLE_STRICT_HASH_VERIFICATION, 0));
+	cl_git_pass(git_odb_read(&_obj, _odb, &_oid));
+
+	assert_object_contains(_obj, objs[0].content);
+}
+
+void test_odb_backend_simple__read_prefix_succeeds(void)
+{
+	const fake_object objs[] = {
+		{ "f6ea0495187600e7b2288c8ac19c5886383a4632", "foobar" },
+		{ NULL, NULL }
+	};
+
+	setup_backend(objs);
+
+	cl_git_pass(git_oid_fromstr(&_oid, "f6ea0495187600e7b2288c8ac19c5886383a4632"));
+	cl_git_pass(git_odb_read(&_obj, _odb, &_oid));
+
+	assert_object_contains(_obj, objs[0].content);
+}
+
+void test_odb_backend_simple__read_prefix_of_nonexisting_object_fails(void)
+{
+	const fake_object objs[] = {
+		{ "f6ea0495187600e7b2288c8ac19c5886383a4632", "foobar" },
+		{ NULL, NULL }
+	};
+	char *hash = "f6ea0495187600e8";
+
+	setup_backend(objs);
+
+	cl_git_pass(git_oid_fromstrn(&_oid, hash, strlen(hash)));
+	cl_git_fail_with(GIT_ENOTFOUND, git_odb_read(&_obj, _odb, &_oid));
+}
+
+void test_odb_backend_simple__read_with_ambiguous_prefix_fails(void)
+{
+	const fake_object objs[] = {
+		{ "1234567890111111111111111111111111111111", "first content" },
+		{ "1234567890222222222222222222222222222222", "second content" },
+		{ NULL, NULL }
+	};
+
+	setup_backend(objs);
+
+	cl_git_pass(git_oid_fromstr(&_oid, objs[0].oid));
+	cl_git_fail_with(GIT_EAMBIGUOUS, git_odb_read_prefix(&_obj, _odb, &_oid, 7));
+}
+
+void test_odb_backend_simple__read_with_highly_ambiguous_prefix(void)
+{
+	const fake_object objs[] = {
+		{ "1234567890111111111111111111111111111111", "first content" },
+		{ "1234567890111111111111111111111111111112", "second content" },
+		{ NULL, NULL }
+	};
+
+	setup_backend(objs);
+
+	cl_git_pass(git_oid_fromstr(&_oid, objs[0].oid));
+	cl_git_pass(git_libgit2_opts(GIT_OPT_ENABLE_STRICT_HASH_VERIFICATION, 0));
+	cl_git_fail_with(GIT_EAMBIGUOUS, git_odb_read_prefix(&_obj, _odb, &_oid, 39));
+	cl_git_pass(git_odb_read_prefix(&_obj, _odb, &_oid, 40));
+	assert_object_contains(_obj, objs[0].content);
+}
+
+void test_odb_backend_simple__exists_succeeds(void)
+{
+	const fake_object objs[] = {
+		{ "f6ea0495187600e7b2288c8ac19c5886383a4632", "foobar" },
+		{ NULL, NULL }
+	};
+
+	setup_backend(objs);
+
+	cl_git_pass(git_oid_fromstr(&_oid, objs[0].oid));
+	cl_assert(git_odb_exists(_odb, &_oid));
+}
+
+void test_odb_backend_simple__exists_fails_for_nonexisting_object(void)
+{
+	const fake_object objs[] = {
+		{ "f6ea0495187600e7b2288c8ac19c5886383a4632", "foobar" },
+		{ NULL, NULL }
+	};
+
+	setup_backend(objs);
+
+	cl_git_pass(git_oid_fromstr(&_oid, "f6ea0495187600e7b2288c8ac19c5886383a4633"));
+	cl_assert(git_odb_exists(_odb, &_oid) == 0);
+}
+
+void test_odb_backend_simple__exists_prefix_succeeds(void)
+{
+	const fake_object objs[] = {
+		{ "1234567890111111111111111111111111111111", "first content" },
+		{ "1234567890222222222222222222222222222222", "second content" },
+		{ NULL, NULL }
+	};
+	git_oid found;
+
+	setup_backend(objs);
+
+	cl_git_pass(git_oid_fromstr(&_oid, objs[0].oid));
+	cl_git_pass(git_odb_exists_prefix(&found, _odb, &_oid, 12));
+	cl_assert(git_oid_equal(&found, &_oid));
+}
+
+void test_odb_backend_simple__exists_with_ambiguous_prefix_fails(void)
+{
+	const fake_object objs[] = {
+		{ "1234567890111111111111111111111111111111", "first content" },
+		{ "1234567890222222222222222222222222222222", "second content" },
+		{ NULL, NULL }
+	};
+
+	setup_backend(objs);
+
+	cl_git_pass(git_oid_fromstr(&_oid, objs[0].oid));
+	cl_git_fail_with(GIT_EAMBIGUOUS, git_odb_exists_prefix(NULL, _odb, &_oid, 7));
+}
+
+void test_odb_backend_simple__exists_with_highly_ambiguous_prefix(void)
+{
+	const fake_object objs[] = {
+		{ "1234567890111111111111111111111111111111", "first content" },
+		{ "1234567890111111111111111111111111111112", "second content" },
+		{ NULL, NULL }
+	};
+	git_oid found;
+
+	setup_backend(objs);
+
+	cl_git_pass(git_oid_fromstr(&_oid, objs[0].oid));
+	cl_git_pass(git_libgit2_opts(GIT_OPT_ENABLE_STRICT_HASH_VERIFICATION, 0));
+	cl_git_fail_with(GIT_EAMBIGUOUS, git_odb_exists_prefix(&found, _odb, &_oid, 39));
+	cl_git_pass(git_odb_exists_prefix(&found, _odb, &_oid, 40));
+	cl_assert(git_oid_equal(&found, &_oid));
+}