[PATCH v7 5/9] environment: move askpass_program into repo_config_values

[Tian Yuchen <cat@malon.dev>]

The global variable 'askpass_program' stores the path to the program
used to prompt the user for credentials. Move it into repo_config_values
to continue the libification effort.

While it is uncommon for a single process to require different askpass
programs for different repositories, maintaining this value as a mutable
global string is a blocker for libification. Global heap-allocated
strings introduce thread-safety issues in a multi-repo environment.

Move 'askpass_program' into 'struct repo_config_values' to eliminate
this global state. The memory is now safely managed and freed via
'repo_config_values_clear()'.

Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Ayush Chandekar <ayu.chandekar@gmail.com>
Mentored-by: Olamide Caleb Bello <belkid98@gmail.com>
Signed-off-by: Tian Yuchen <cat@malon.dev>
---
 environment.c | 6 ++++--
 environment.h | 1 +
 prompt.c      | 3 ++-
 3 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/environment.c b/environment.c
index a1204fdcb2..3782bf68aa 100644
--- a/environment.c
+++ b/environment.c
@@ -462,8 +462,8 @@ int git_default_core_config(const char *var, const char *value,
 	}
 
 	if (!strcmp(var, "core.askpass")) {
-		FREE_AND_NULL(askpass_program);
-		return git_config_string(&askpass_program, var, value);
+		FREE_AND_NULL(cfg->askpass_program);
+		return git_config_string(&cfg->askpass_program, var, value);
 	}
 
 	if (!strcmp(var, "core.excludesfile")) {
@@ -724,6 +724,7 @@ void repo_config_values_init(struct repo_config_values *cfg)
 	cfg->excludes_file = NULL;
 	cfg->editor_program = NULL;
 	cfg->pager_program = NULL;
+	cfg->askpass_program = NULL;
 	cfg->apply_sparse_checkout = 0;
 	cfg->branch_track = BRANCH_TRACK_REMOTE;
 	cfg->trust_ctime = 1;
@@ -756,4 +757,5 @@ void repo_config_values_clear(struct repository *repo)
 	FREE_AND_NULL(cfg->excludes_file);
 	FREE_AND_NULL(cfg->editor_program);
 	FREE_AND_NULL(cfg->pager_program);
+	FREE_AND_NULL(cfg->askpass_program);
 }
diff --git a/environment.h b/environment.h
index 22f6697c52..d55b1ba073 100644
--- a/environment.h
+++ b/environment.h
@@ -93,6 +93,7 @@ struct repo_config_values {
 	char *excludes_file;
 	char *editor_program;
 	char *pager_program;
+	char *askpass_program;
 	int apply_sparse_checkout;
 	int trust_ctime;
 	int check_stat;
diff --git a/prompt.c b/prompt.c
index 706fba2a50..d8d74c7e37 100644
--- a/prompt.c
+++ b/prompt.c
@@ -3,6 +3,7 @@
 #include "git-compat-util.h"
 #include "parse.h"
 #include "environment.h"
+#include "repository.h"
 #include "run-command.h"
 #include "strbuf.h"
 #include "prompt.h"
@@ -51,7 +52,7 @@ char *git_prompt(const char *prompt, int flags)
 
 		askpass = getenv("GIT_ASKPASS");
 		if (!askpass)
-			askpass = askpass_program;
+			askpass = repo_config_values(the_repository)->askpass_program;
 		if (!askpass)
 			askpass = getenv("SSH_ASKPASS");
 		if (askpass && *askpass)
-- 
2.43.0