repository: Change ownership semantics

The ownership semantics have been changed all over the library to be
consistent. There are no more "borrowed" or duplicated references.

Main changes:

	- `git_repository_open2` and `3` have been dropped.

	- Added setters and getters to hotswap all the repository owned
	objects:

		`git_repository_index`
		`git_repository_set_index`
		`git_repository_odb`
		`git_repository_set_odb`
		`git_repository_config`
		`git_repository_set_config`
		`git_repository_workdir`
		`git_repository_set_workdir`

	Now working directories/index files/ODBs and so on can be
	hot-swapped after creating a repository and between operations.

	- All these objects now have proper ownership semantics with
	refcounting: they all require freeing after they are no longer
	needed (the repository always keeps its internal reference).

	- Repository open and initialization has been updated to keep in
	mind the configuration files. Bare repositories are now always
	detected, and a default config file is created on init.

	- All the tests affected by these changes have been dropped from the
	old test suite and ported to the new one.

1 files changed, 24 insertions, 0 deletions

diff --git a/src/util.h b/src/util.h
index fbf9012a3..2b239a0bf 100644
--- a/src/util.h
+++ b/src/util.h
@@ -129,4 +129,28 @@ extern void **git__bsearch(const void *key, void **base, size_t nmemb,
 
 extern int git__strcmp_cb(const void *a, const void *b);
 
+typedef struct {
+	short refcount;
+	void *owner;
+} git_refcount;
+
+typedef void (*git_refcount_freeptr)(void *r);
+
+#define GIT_REFCOUNT_INC(r) { \
+	((git_refcount *)(r))->refcount++; \
+}
+
+#define GIT_REFCOUNT_DEC(_r, do_free) { \
+	git_refcount *r = (git_refcount *)(_r); \
+	r->refcount--; \
+	if (r->refcount == 0 && r->owner == NULL) { do_free(_r); } \
+}
+
+#define GIT_REFCOUNT_OWN(r, o) { \
+	((git_refcount *)(r))->owner = o; \
+}
+
+#define GIT_REFCOUNT_OWNER(r) (((git_refcount *)(r))->owner)
+
+
 #endif /* INCLUDE_util_h__ */