config: make dependency on repo in read_early_config() explicit

The `read_early_config()` function can be used to read configuration
where a repository has not yet been set up. As such, it is optional
whether or not `the_repository` has already been initialized. If it was
initialized we use its commondir and gitdir. If not, the function will
try to detect the Git directories by itself and, if found, also parse
their config files.

This means that we implicitly rely on `the_repository`. Make this
dependency explicit by passing a `struct repository`. This allows us to
again drop the `USE_THE_REPOSITORY_VARIABLE` define in "config.c".

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

alias.c

@@ -1,3 +1,5 @@
+#define USE_THE_REPOSITORY_VARIABLE
+
 #include "git-compat-util.h"
 #include "alias.h"
 #include "config.h"
@@ -37,7 +39,7 @@ char *alias_lookup(const char *alias)
 {
 	struct config_alias_data data = { alias, NULL };
 
-	read_early_config(config_alias_cb, &data);
+	read_early_config(the_repository, config_alias_cb, &data);
 
 	return data.v;
 }
@@ -46,7 +48,7 @@ void list_aliases(struct string_list *list)
 {
 	struct config_alias_data data = { NULL, NULL, list };
 
-	read_early_config(config_alias_cb, &data);
+	read_early_config(the_repository, config_alias_cb, &data);
 }
 
 void quote_cmdline(struct strbuf *buf, const char **argv)

config.c

@@ -6,8 +6,6 @@
  *
  */
 
-#define USE_THE_REPOSITORY_VARIABLE
-
 #include "git-compat-util.h"
 #include "abspath.h"
 #include "advice.h"
@@ -2204,7 +2202,7 @@ static void configset_iter(struct config_set *set, config_fn_t fn, void *data)
 	}
 }
 
-void read_early_config(config_fn_t cb, void *data)
+void read_early_config(struct repository *repo, config_fn_t cb, void *data)
 {
 	struct config_options opts = {0};
 	struct strbuf commondir = STRBUF_INIT;
@@ -2212,9 +2210,9 @@ void read_early_config(config_fn_t cb, void *data)
 
 	opts.respect_includes = 1;
 
-	if (have_git_dir()) {
-		opts.commondir = repo_get_common_dir(the_repository);
-		opts.git_dir = repo_get_git_dir(the_repository);
+	if (repo && repo->gitdir) {
+		opts.commondir = repo_get_common_dir(repo);
+		opts.git_dir = repo_get_git_dir(repo);
 	/*
 	 * When setup_git_directory() was not yet asked to discover the
 	 * GIT_DIR, we ask discover_git_directory() to figure out whether there

config.h

@@ -198,7 +198,7 @@ int git_config_from_parameters(config_fn_t fn, void *data);
  * `the_repository` has not yet been set up, try to discover the Git
  * directory to read the configuration from.
  */
-void read_early_config(config_fn_t cb, void *data);
+void read_early_config(struct repository *repo, config_fn_t cb, void *data);
 
 /*
  * Read config but only enumerate system and global settings.

help.c

@@ -618,7 +618,7 @@ const char *help_unknown_cmd(const char *cmd)
 	memset(&other_cmds, 0, sizeof(other_cmds));
 	memset(&aliases, 0, sizeof(aliases));
 
-	read_early_config(git_unknown_cmd_config, NULL);
+	read_early_config(the_repository, git_unknown_cmd_config, NULL);
 
 	/*
 	 * Disable autocorrection prompt in a non-interactive session

pager.c

@@ -1,3 +1,5 @@
+#define USE_THE_REPOSITORY_VARIABLE
+
 #include "git-compat-util.h"
 #include "config.h"
 #include "editor.h"
@@ -92,7 +94,8 @@ const char *git_pager(int stdout_is_tty)
 	pager = getenv("GIT_PAGER");
 	if (!pager) {
 		if (!pager_program)
-			read_early_config(core_pager_config, NULL);
+			read_early_config(the_repository,
+					  core_pager_config, NULL);
 		pager = pager_program;
 	}
 	if (!pager)
@@ -298,7 +301,7 @@ int check_pager_config(const char *cmd)
 	data.want = -1;
 	data.value = NULL;
 
-	read_early_config(pager_command_config, &data);
+	read_early_config(the_repository, pager_command_config, &data);
 
 	if (data.value)
 		pager_program = data.value;

t/helper/test-config.c

@@ -96,7 +96,8 @@ int cmd__config(int argc, const char **argv)
 	struct config_set cs;
 
 	if (argc == 3 && !strcmp(argv[1], "read_early_config")) {
-		read_early_config(early_config_cb, (void *)argv[2]);
+		read_early_config(the_repository, early_config_cb,
+				  (void *)argv[2]);
 		return 0;
 	}
 

trace2/tr2_cfg.c

@@ -1,3 +1,5 @@
+#define USE_THE_REPOSITORY_VARIABLE
+
 #include "git-compat-util.h"
 #include "config.h"
 #include "strbuf.h"
@@ -124,7 +126,7 @@ void tr2_cfg_list_config_fl(const char *file, int line)
 	struct tr2_cfg_data data = { file, line };
 
 	if (tr2_cfg_load_patterns() > 0)
-		read_early_config(tr2_cfg_cb, &data);
+		read_early_config(the_repository, tr2_cfg_cb, &data);
 }
 
 void tr2_list_env_vars_fl(const char *file, int line)