env--helper: write to opt->value in parseopt helper

peff · gitster · commit 424e28fcadfe · 2020-09-30T12:53:47.000-07:00
We use OPT_CALLBACK_F() to call the option_parse_type() callback,
passing it the address of "cmdmode" as the value to write to. But the
callback doesn't look at opt-&gt;value at all, and instead writes to a
global variable.

This works out because that's the same global variable we happen to pass
in, but it's rather confusing.  Let's use the passed-in value instead.
We'll also make "cmdmode" a local variable of the main function,
ensuring we can't make the same mistake again.

Signed-off-by: Jeff King &lt;peff@peff.net&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
diff --git a/builtin/env--helper.c b/builtin/env--helper.c
@@ -7,18 +7,20 @@ static char const * const env__helper_usage[] = {
 	NULL
 };
 
-static enum {
+enum cmdmode {
 	ENV_HELPER_TYPE_BOOL = 1,
 	ENV_HELPER_TYPE_ULONG
-} cmdmode = 0;
+};
 
 static int option_parse_type(const struct option *opt, const char *arg,
 			     int unset)
 {
+	enum cmdmode *cmdmode = opt->value;
+
 	if (!strcmp(arg, "bool"))
-		cmdmode = ENV_HELPER_TYPE_BOOL;
+		*cmdmode = ENV_HELPER_TYPE_BOOL;
 	else if (!strcmp(arg, "ulong"))
-		cmdmode = ENV_HELPER_TYPE_ULONG;
+		*cmdmode = ENV_HELPER_TYPE_ULONG;
 	else
 		die(_("unrecognized --type argument, %s"), arg);
 
@@ -33,6 +35,7 @@ int cmd_env__helper(int argc, const char **argv, const char *prefix)
 	int ret;
 	int ret_int, default_int;
 	unsigned long ret_ulong, default_ulong;
+	enum cmdmode cmdmode = 0;
 	struct option opts[] = {
 		OPT_CALLBACK_F(0, "type", &cmdmode, N_("type"),
 			       N_("value is given this type"), PARSE_OPT_NONEG,
