Subject: [Outreachy PATCH v4 3/3] environment: move "branch.autoSetupMerge" into `struct repo_config_values`

From: Olamide Caleb Bello <[email-masked]>
Date: Sat, 24 Jan 2026 12:55:06 +0100

The config value `brach.autoSetupMerge` is parsed in
`git_default_branch_config()` and stored in the global variable
`git_branch_track`. This global variable can be overwritten
by another repository when multiple Git repos run in the the same process.

Move this value into `struct repo_config_values` in the_repository to
retain current behaviours and move towards libifying Git.
Since the variable is no longer a global variable, it has been renamed to
`branch_track` in the struct `repo_config_values`.

Suggested-by: Phillip Wood <[email-masked]>
Mentored-by: Christian Couder <[email-masked]>
Mentored-by: Usman Akinyemi <[email-masked]>
Signed-off-by: Olamide Caleb Bello <[email-masked]>
---
 branch.h                    |  2 --
 builtin/branch.c            |  2 +-
 builtin/checkout.c          |  2 +-
 builtin/push.c              |  2 +-
 builtin/submodule--helper.c |  2 +-
 environment.c               | 12 +++++++-----
 environment.h               |  4 ++++
 7 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/branch.h b/branch.h
index ec2f35fda4..3dc6e2a0ff 100644
--- a/branch.h
+++ b/branch.h
@@ -15,8 +15,6 @@ enum branch_track {
 	BRANCH_TRACK_SIMPLE,
 };
 
-extern enum branch_track git_branch_track;
-
 /* Functions for acting on the information about branches. */
 
 /**
diff --git a/builtin/branch.c b/builtin/branch.c
index c577b5d20f..7d27951a7e 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -795,7 +795,7 @@ int cmd_branch(int argc,
 	if (!sorting_options.nr)
 		string_list_append(&sorting_options, "refname");
 
-	track = git_branch_track;
+	track = the_repository->config_values.branch_track;
 
 	head = refs_resolve_refdup(get_main_ref_store(the_repository), "HEAD",
 				   0, &head_oid, NULL);
diff --git a/builtin/checkout.c b/builtin/checkout.c
index 261699e2f5..ba6fea9aee 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -1631,7 +1631,7 @@ static int checkout_branch(struct checkout_opts *opts,
 		if (opts->track != BRANCH_TRACK_UNSPECIFIED)
 			die(_("'%s' cannot be used with '%s'"), "--detach", "-t");
 	} else if (opts->track == BRANCH_TRACK_UNSPECIFIED)
-		opts->track = git_branch_track;
+		opts->track = the_repository->config_values.branch_track;
 
 	if (new_branch_info->name && !new_branch_info->commit)
 		die(_("Cannot switch branch to a non-commit '%s'"),
diff --git a/builtin/push.c b/builtin/push.c
index 5b6cebbb85..7be20a1035 100644
--- a/builtin/push.c
+++ b/builtin/push.c
@@ -162,7 +162,7 @@ static NORETURN void die_push_simple(struct branch *branch,
 		advice_pushdefault_maybe = _("\n"
 				 "To choose either option permanently, "
 				 "see push.default in 'git help config'.\n");
-	if (git_branch_track != BRANCH_TRACK_SIMPLE)
+	if (the_repository->config_values.branch_track != BRANCH_TRACK_SIMPLE)
 		advice_automergesimple_maybe = _("\n"
 				 "To avoid automatically configuring "
 				 "an upstream branch when its name\n"
diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index d537ab087a..f2b6f027d7 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -3128,7 +3128,7 @@ static int module_create_branch(int argc, const char **argv, const char *prefix,
 	};
 
 	repo_config(the_repository, git_default_config, NULL);
-	track = git_branch_track;
+	track = the_repository->config_values.branch_track;
 	argc = parse_options(argc, argv, prefix, options, usage, 0);
 
 	if (argc != 3)
diff --git a/environment.c b/environment.c
index 269cac6d6e..de8721657e 100644
--- a/environment.c
+++ b/environment.c
@@ -66,7 +66,6 @@ enum auto_crlf auto_crlf = AUTO_CRLF_FALSE;
 enum eol core_eol = EOL_UNSET;
 int global_conv_flags_eol = CONV_EOL_RNDTRP_WARN;
 char *check_roundtrip_encoding;
-enum branch_track git_branch_track = BRANCH_TRACK_REMOTE;
 enum rebase_setup_type autorebase = AUTOREBASE_NEVER;
 enum push_default_type push_default = PUSH_DEFAULT_UNSPECIFIED;
 #ifndef OBJECT_CREATION_MODE
@@ -607,18 +606,20 @@ static int git_default_i18n_config(const char *var, const char *value)
 
 static int git_default_branch_config(const char *var, const char *value)
 {
+	struct repo_config_values *cfg = &the_repository->config_values;
+
 	if (!strcmp(var, "branch.autosetupmerge")) {
 		if (value && !strcmp(value, "always")) {
-			git_branch_track = BRANCH_TRACK_ALWAYS;
+			cfg->branch_track = BRANCH_TRACK_ALWAYS;
 			return 0;
 		} else if (value && !strcmp(value, "inherit")) {
-			git_branch_track = BRANCH_TRACK_INHERIT;
+			cfg->branch_track = BRANCH_TRACK_INHERIT;
 			return 0;
 		} else if (value && !strcmp(value, "simple")) {
-			git_branch_track = BRANCH_TRACK_SIMPLE;
+			cfg->branch_track = BRANCH_TRACK_SIMPLE;
 			return 0;
 		}
-		git_branch_track = git_config_bool(var, value);
+		cfg->branch_track = git_config_bool(var, value);
 		return 0;
 	}
 	if (!strcmp(var, "branch.autosetuprebase")) {
@@ -761,4 +762,5 @@ void repo_config_values_init(struct repo_config_values *cfg)
 {
 	cfg->attributes_file = NULL;
 	cfg->apply_sparse_checkout = 0;
+	cfg->branch_track = BRANCH_TRACK_REMOTE;
 }
diff --git a/environment.h b/environment.h
index ddce69c6ba..27161d56ab 100644
--- a/environment.h
+++ b/environment.h
@@ -2,6 +2,7 @@
 #define ENVIRONMENT_H
 
 #include "repo-settings.h"
+#include "branch.h"
 
 /* Double-check local_repo_env below if you add to this list. */
 #define GIT_DIR_ENVIRONMENT "GIT_DIR"
@@ -88,6 +89,9 @@ struct repo_config_values {
 	/* section "core" config values */
 	char *attributes_file;
 	int apply_sparse_checkout;
+
+	/* section "branch" config values */
+	enum branch_track branch_track;
 };
 
 /*
-- 
2.34.1