Reorganize diff and add basic diff driver

This is a significant reorganization of the diff code to break it
into a set of more clearly distinct files and to document the new
organization.  Hopefully this will make the diff code easier to
understand and to extend.

This adds a new `git_diff_driver` object that looks of diff driver
information from the attributes and the config so that things like
function content in diff headers can be provided.  The full driver
spec is not implemented in the commit - this is focused on the
reorganization of the code and putting the driver hooks in place.

This also removes a few #includes from src/repository.h that were
overbroad, but as a result required extra #includes in a variety
of places since including src/repository.h no longer results in
pulling in the whole world.

4 files changed, 17 insertions, 13 deletions

diff --git a/tests-clar/refs/delete.c b/tests-clar/refs/delete.c
index 053f41229..973768aeb 100644
--- a/tests-clar/refs/delete.c
+++ b/tests-clar/refs/delete.c
@@ -1,7 +1,8 @@
 #include "clar_libgit2.h"
 
-#include "repository.h"
+#include "fileops.h"
 #include "git2/reflog.h"
+#include "git2/refdb.h"
 #include "reflog.h"
 #include "ref_helpers.h"
 
@@ -31,7 +32,7 @@ void test_refs_delete__packed_loose(void)
 	git_buf temp_path = GIT_BUF_INIT;
 
 	/* Ensure the loose reference exists on the file system */
-	cl_git_pass(git_buf_joinpath(&temp_path, g_repo->path_repository, packed_test_head_name));
+	cl_git_pass(git_buf_joinpath(&temp_path, git_repository_path(g_repo), packed_test_head_name));
 	cl_assert(git_path_exists(temp_path.ptr));
 
 	/* Lookup the reference */
diff --git a/tests-clar/refs/pack.c b/tests-clar/refs/pack.c
index 412c4c5fd..d8d5cc6d0 100644
--- a/tests-clar/refs/pack.c
+++ b/tests-clar/refs/pack.c
@@ -1,8 +1,10 @@
 #include "clar_libgit2.h"
 
-#include "repository.h"
+#include "fileops.h"
 #include "git2/reflog.h"
+#include "git2/refdb.h"
 #include "reflog.h"
+#include "refs.h"
 #include "ref_helpers.h"
 
 static const char *loose_tag_ref_name = "refs/tags/e90810b";
@@ -33,7 +35,7 @@ void test_refs_pack__empty(void)
    // create a packfile for an empty folder
 	git_buf temp_path = GIT_BUF_INIT;
 
-	cl_git_pass(git_buf_join_n(&temp_path, '/', 3, g_repo->path_repository, GIT_REFS_HEADS_DIR, "empty_dir"));
+	cl_git_pass(git_buf_join_n(&temp_path, '/', 3, git_repository_path(g_repo), GIT_REFS_HEADS_DIR, "empty_dir"));
 	cl_git_pass(git_futils_mkdir_r(temp_path.ptr, NULL, GIT_REFS_DIR_MODE));
 	git_buf_free(&temp_path);
 
@@ -60,7 +62,7 @@ void test_refs_pack__loose(void)
 	packall();
 
 	/* Ensure the packed-refs file exists */
-	cl_git_pass(git_buf_joinpath(&temp_path, g_repo->path_repository, GIT_PACKEDREFS_FILE));
+	cl_git_pass(git_buf_joinpath(&temp_path, git_repository_path(g_repo), GIT_PACKEDREFS_FILE));
 	cl_assert(git_path_exists(temp_path.ptr));
 
 	/* Ensure the known ref can still be looked up but is now packed */
@@ -69,7 +71,7 @@ void test_refs_pack__loose(void)
 	cl_assert_equal_s(reference->name, loose_tag_ref_name);
 
 	/* Ensure the known ref has been removed from the loose folder structure */
-	cl_git_pass(git_buf_joinpath(&temp_path, g_repo->path_repository, loose_tag_ref_name));
+	cl_git_pass(git_buf_joinpath(&temp_path, git_repository_path(g_repo), loose_tag_ref_name));
 	cl_assert(!git_path_exists(temp_path.ptr));
 
 	git_reference_free(reference);
diff --git a/tests-clar/refs/reflog/reflog.c b/tests-clar/refs/reflog/reflog.c
index 1cd0ddd92..095cabf04 100644
--- a/tests-clar/refs/reflog/reflog.c
+++ b/tests-clar/refs/reflog/reflog.c
@@ -1,6 +1,6 @@
 #include "clar_libgit2.h"
 
-#include "repository.h"
+#include "fileops.h"
 #include "git2/reflog.h"
 #include "reflog.h"
 
diff --git a/tests-clar/refs/rename.c b/tests-clar/refs/rename.c
index 5ab84c48e..543bc4d62 100644
--- a/tests-clar/refs/rename.c
+++ b/tests-clar/refs/rename.c
@@ -1,8 +1,9 @@
 #include "clar_libgit2.h"
 
-#include "repository.h"
+#include "fileops.h"
 #include "git2/reflog.h"
 #include "reflog.h"
+#include "refs.h"
 #include "ref_helpers.h"
 
 static const char *loose_tag_ref_name = "refs/tags/e90810b";
@@ -38,7 +39,7 @@ void test_refs_rename__loose(void)
 	const char *new_name = "refs/tags/Nemo/knows/refs.kung-fu";
 
 	/* Ensure the ref doesn't exist on the file system */
-	cl_git_pass(git_buf_joinpath(&temp_path, g_repo->path_repository, new_name));
+	cl_git_pass(git_buf_joinpath(&temp_path, git_repository_path(g_repo), new_name));
 	cl_assert(!git_path_exists(temp_path.ptr));
 
 	/* Retrieval of the reference to rename */
@@ -64,7 +65,7 @@ void test_refs_rename__loose(void)
 	cl_assert(reference_is_packed(new_ref) == 0);
 
 	/* ...and the ref can be found in the file system */
-	cl_git_pass(git_buf_joinpath(&temp_path, g_repo->path_repository, new_name));
+	cl_git_pass(git_buf_joinpath(&temp_path, git_repository_path(g_repo), new_name));
 	cl_assert(git_path_exists(temp_path.ptr));
 
 	git_reference_free(new_ref);
@@ -80,7 +81,7 @@ void test_refs_rename__packed(void)
 	const char *brand_new_name = "refs/heads/brand_new_name";
 
 	/* Ensure the ref doesn't exist on the file system */
-	cl_git_pass(git_buf_joinpath(&temp_path, g_repo->path_repository, packed_head_name));
+	cl_git_pass(git_buf_joinpath(&temp_path, git_repository_path(g_repo), packed_head_name));
 	cl_assert(!git_path_exists(temp_path.ptr));
 
 	/* The reference can however be looked-up... */
@@ -106,7 +107,7 @@ void test_refs_rename__packed(void)
 	cl_assert(reference_is_packed(new_ref) == 0);
 
 	/* ...and the ref now happily lives in the file system */
-	cl_git_pass(git_buf_joinpath(&temp_path, g_repo->path_repository, brand_new_name));
+	cl_git_pass(git_buf_joinpath(&temp_path, git_repository_path(g_repo), brand_new_name));
 	cl_assert(git_path_exists(temp_path.ptr));
 
 	git_reference_free(new_ref);
@@ -122,7 +123,7 @@ void test_refs_rename__packed_doesnt_pack_others(void)
 	const char *brand_new_name = "refs/heads/brand_new_name";
 
 	/* Ensure the other reference exists on the file system */
-	cl_git_pass(git_buf_joinpath(&temp_path, g_repo->path_repository, packed_test_head_name));
+	cl_git_pass(git_buf_joinpath(&temp_path, git_repository_path(g_repo), packed_test_head_name));
 	cl_assert(git_path_exists(temp_path.ptr));
 
 	/* Lookup the other reference */