common: support custom repository extensionsethomson/extensions

Allow users to specify additional repository extensions that they want
to support.  For example, callers can specify that they support
`preciousObjects` and then may open repositories that support
`extensions.preciousObjects`.

Similarly, callers may opt out of supporting extensions that the library
itself supports.

1 files changed, 28 insertions, 0 deletions

diff --git a/tests/repo/extensions.c b/tests/repo/extensions.c
index 8ba89f1a9..e7772acd5 100644
--- a/tests/repo/extensions.c
+++ b/tests/repo/extensions.c
@@ -19,6 +19,7 @@ void test_repo_extensions__initialize(void)
 void test_repo_extensions__cleanup(void)
 {
 	cl_git_sandbox_cleanup();
+	cl_git_pass(git_libgit2_opts(GIT_OPT_SET_EXTENSIONS, NULL, 0));
 }
 
 void test_repo_extensions__builtin(void)
@@ -33,6 +34,19 @@ void test_repo_extensions__builtin(void)
 	git_repository_free(extended);
 }
 
+void test_repo_extensions__negate_builtin(void)
+{
+	const char *in[] = { "foo", "!noop", "baz" };
+	git_repository *extended;
+
+	cl_repo_set_string(repo, "extensions.noop", "foobar");
+
+	cl_git_pass(git_libgit2_opts(GIT_OPT_SET_EXTENSIONS, in, ARRAY_SIZE(in)));
+
+	cl_git_fail(git_repository_open(&extended, "empty_bare.git"));
+	git_repository_free(extended);
+}
+
 void test_repo_extensions__unsupported(void)
 {
 	git_repository *extended = NULL;
@@ -42,3 +56,17 @@ void test_repo_extensions__unsupported(void)
 	cl_git_fail(git_repository_open(&extended, "empty_bare.git"));
 	git_repository_free(extended);
 }
+
+void test_repo_extensions__adds_extension(void)
+{
+	const char *in[] = { "foo", "!noop", "newextension", "baz" };
+	git_repository *extended;
+
+	cl_repo_set_string(repo, "extensions.newextension", "foobar");
+	cl_git_pass(git_libgit2_opts(GIT_OPT_SET_EXTENSIONS, in, ARRAY_SIZE(in)));
+
+	cl_git_pass(git_repository_open(&extended, "empty_bare.git"));
+	cl_assert(git_repository_path(extended) != NULL);
+	cl_assert(git__suffixcmp(git_repository_path(extended), "/") == 0);
+	git_repository_free(extended);
+}