[PATCH 1/3] run-command: optionally clear git environment

@@ -2,6 +2,10 @@
 #include "run-command.h"
 #include "exec_cmd.h"
 
+static const char* git_env_list[] = { ALTERNATE_DB_ENVIRONMENT, DB_ENVIRONMENT,
+			CONFIG_ENVIRONMENT, GIT_DIR_ENVIRONMENT,
+			GRAFT_ENVIRONMENT, INDEX_ENVIRONMENT, NULL };
+
 static inline void close_pair(int fd[2])
 {
 	close(fd[0]);

@@ -153,6 +157,8 @@ static void prepare_run_command_v_opt(struct child_process *cmd,
 	cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 	cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 	cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
+	if (opt & RUN_COMMAND_CLEAR_GIT_ENV)
+		cmd->env = git_env_list;
 }
 
 int run_command_v_opt(const char **argv, int opt)

@@ -33,6 +33,7 @@ int run_command(struct child_process *);
 #define RUN_COMMAND_NO_STDIN 1
 #define RUN_GIT_CMD	     2	/*If this is to be git sub-command */
 #define RUN_COMMAND_STDOUT_TO_STDERR 4
+#define RUN_COMMAND_CLEAR_GIT_ENV	(1 << 3)
 int run_command_v_opt(const char **argv, int opt);
 int run_command_v_opt_cd(const char **argv, int opt, const char *dir);