config_file: embed file in diskfile parse data

The config file code needs to keep track of the actual
`git_config_file` structure, as it not only contains the path
of the current configuration file, but it also keeps tracks of
all includes of that file. Right now, we keep track of that
structure via the `git_config_parser`, but as that's supposed to
be a backend generic implementation of configuration parsing it's
a layering violation to have it in there.

Switch over the config file backend to use its own config file
structure that's embedded in the backend parse data. This allows
us to switch over the generic config parser to avoid using the
`git_config_file` structure.

src/config_file.c

@@ -55,7 +55,7 @@ typedef struct {
 
 typedef struct {
 	const git_repository *repo;
-	const char *file_path;
+	git_config_file *file;
 	git_config_entries *entries;
 	git_config_level_t level;
 	unsigned int depth;
@@ -677,8 +677,7 @@ static char *escape_value(const char *ptr)
 	return git_buf_detach(&buf);
 }
 
-static int parse_include(git_config_parser *reader,
-	diskfile_parse_state *parse_data, const char *file)
+static int parse_include(diskfile_parse_state *parse_data, const char *file)
 {
 	git_config_file *include;
 	git_buf path = GIT_BUF_INIT;
@@ -688,7 +687,7 @@ static int parse_include(git_config_parser *reader,
 	if (!file)
 		return 0;
 
-	if ((result = git_path_dirname_r(&path, reader->file->path)) < 0)
+	if ((result = git_path_dirname_r(&path, parse_data->file->path)) < 0)
 		return result;
 
 	dir = git_buf_detach(&path);
@@ -698,7 +697,7 @@ static int parse_include(git_config_parser *reader,
 	if (result < 0)
 		return result;
 
-	include = git_array_alloc(reader->file->includes);
+	include = git_array_alloc(parse_data->file->includes);
 	GIT_ERROR_CHECK_ALLOC(include);
 	memset(include, 0, sizeof(*include));
 	git_array_init(include->includes);
@@ -783,8 +782,7 @@ static const struct {
 	{ "gitdir/i:", conditional_match_gitdir_i }
 };
 
-static int parse_conditional_include(git_config_parser *reader,
-	diskfile_parse_state *parse_data, const char *section, const char *file)
+static int parse_conditional_include(diskfile_parse_state *parse_data, const char *section, const char *file)
 {
 	char *condition;
 	size_t i;
@@ -802,12 +800,12 @@ static int parse_conditional_include(git_config_parser *reader,
 
 		if ((error = conditions[i].matches(&matches,
 						   parse_data->repo,
-						   parse_data->file_path,
+						   parse_data->file->path,
 						   condition + strlen(conditions[i].prefix))) < 0)
 			break;
 
 		if (matches)
-			error = parse_include(reader, parse_data, file);
+			error = parse_include(parse_data, file);
 
 		break;
 	}
@@ -831,6 +829,7 @@ static int read_on_variable(
 	const char *c;
 	int result = 0;
 
+	GIT_UNUSED(reader);
 	GIT_UNUSED(line);
 	GIT_UNUSED(line_len);
 
@@ -863,11 +862,10 @@ static int read_on_variable(
 
 	/* Add or append the new config option */
 	if (!git__strcmp(entry->name, "include.path"))
-		result = parse_include(reader, parse_data, entry->value);
+		result = parse_include(parse_data, entry->value);
 	else if (!git__prefixcmp(entry->name, "includeif.") &&
 	         !git__suffixcmp(entry->name, ".path"))
-		result = parse_conditional_include(reader, parse_data,
-						   entry->name, entry->value);
+		result = parse_conditional_include(parse_data, entry->name, entry->value);
 
 	return result;
 }
@@ -901,7 +899,7 @@ static int config_read_buffer(
 	}
 
 	parse_data.repo = repo;
-	parse_data.file_path = file->path;
+	parse_data.file = file;
 	parse_data.entries = entries;
 	parse_data.level = level;
 	parse_data.depth = depth;