Add config level support in the config API

Added `struct git_config_entry`: a git_config_entry contains the key, the value, and the config file level from which a config element was found.
Added `git_config_open_level`: build a single-level focused config object from a multi-level one.

We are now storing `git_config_entry`s in the khash of the config_file

1 files changed, 59 insertions, 0 deletions

diff --git a/tests-clar/config/configlevel.c b/tests-clar/config/configlevel.c
new file mode 100644
index 000000000..d947856fa
--- /dev/null
+++ b/tests-clar/config/configlevel.c
@@ -0,0 +1,59 @@
+#include "clar_libgit2.h"
+
+void test_config_configlevel__adding_the_same_level_twice_returns_EEXISTS(void)
+{
+	int error;
+	git_config *cfg;
+
+	cl_git_pass(git_config_new(&cfg));
+	cl_git_pass(git_config_add_file_ondisk(cfg, cl_fixture("config/config9"),
+		GIT_CONFIG_LEVEL_LOCAL, 0));
+	cl_git_pass(git_config_add_file_ondisk(cfg, cl_fixture("config/config15"),
+		GIT_CONFIG_LEVEL_GLOBAL, 0));
+	error = git_config_add_file_ondisk(cfg, cl_fixture("config/config16"),
+		GIT_CONFIG_LEVEL_GLOBAL, 0);
+
+	cl_git_fail(error);
+	cl_assert_equal_i(GIT_EEXISTS, error);
+
+	git_config_free(cfg);
+}
+
+void test_config_configlevel__can_replace_a_config_file_at_an_existing_level(void)
+{
+	git_config *cfg;
+	const char *s;
+
+	cl_git_pass(git_config_new(&cfg));
+	cl_git_pass(git_config_add_file_ondisk(cfg, cl_fixture("config/config18"),
+		GIT_CONFIG_LEVEL_LOCAL, 1));
+	cl_git_pass(git_config_add_file_ondisk(cfg, cl_fixture("config/config19"),
+		GIT_CONFIG_LEVEL_LOCAL, 1));
+
+	cl_git_pass(git_config_get_string(&s, cfg, "core.stringglobal"));
+	cl_assert_equal_s("don't find me!", s);
+
+	git_config_free(cfg);
+}
+
+void test_config_configlevel__can_read_from_a_single_level_focused_file_after_parent_config_has_been_freed(void)
+{
+	git_config *cfg;
+	git_config *single_level_cfg;
+	const char *s;
+
+	cl_git_pass(git_config_new(&cfg));
+	cl_git_pass(git_config_add_file_ondisk(cfg, cl_fixture("config/config18"),
+		GIT_CONFIG_LEVEL_GLOBAL, 0));
+	cl_git_pass(git_config_add_file_ondisk(cfg, cl_fixture("config/config19"),
+		GIT_CONFIG_LEVEL_LOCAL, 0));
+
+	cl_git_pass(git_config_open_level(&single_level_cfg, cfg, GIT_CONFIG_LEVEL_LOCAL));
+
+	git_config_free(cfg);
+
+	cl_git_pass(git_config_get_string(&s, single_level_cfg, "core.stringglobal"));
+	cl_assert_equal_s("don't find me!", s);
+
+	git_config_free(single_level_cfg);
+}