parse-options: add precision handling for OPTION_NEGBIT

Similar to 0970569 (parse-options: introduce precision handling for
`OPTION_INTEGER`, 2025-04-17) support value variables of different sizes
for OPTION_NEGBIT.  Do that by requiring their "precision" to be set,
casting their "value" pointer accordingly and checking whether the value
fits.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: rscharfe

builtin/rebase.c

@@ -1128,6 +1128,7 @@ int cmd_rebase(int argc,
 			.short_name = 'n',
 			.long_name = "no-stat",
 			.value = &options.flags,
+			.precision = sizeof(options.flags),
 			.help = N_("do not show diffstat of what changed upstream"),
 			.flags = PARSE_OPT_NOARG,
 			.defval = REBASE_DIFFSTAT,

parse-options.c

@@ -157,11 +157,14 @@ static enum parse_opt_result do_get_value(struct parse_opt_ctx_t *p,
 	}
 
 	case OPTION_NEGBIT:
+	{
+		intmax_t value = get_int_value(opt, flags);
 		if (unset)
-			*(int *)opt->value |= opt->defval;
+			value |= opt->defval;
 		else
-			*(int *)opt->value &= ~opt->defval;
-		return 0;
+			value &= ~opt->defval;
+		return set_int_value(opt, flags, value);
+	}
 
 	case OPTION_BITOP:
 		if (unset)
@@ -643,11 +646,11 @@ static void parse_options_check(const struct option *opts)
 		switch (opts->type) {
 		case OPTION_SET_INT:
 		case OPTION_BIT:
+		case OPTION_NEGBIT:
 			if (!signed_int_fits(opts->defval, opts->precision))
 				optbug(opts, "has invalid defval");
 			/* fallthru */
 		case OPTION_COUNTUP:
-		case OPTION_NEGBIT:
 		case OPTION_NUMBER:
 		case OPTION_BITOP:
 			if ((opts->flags & PARSE_OPT_OPTARG) ||

parse-options.h

@@ -250,6 +250,7 @@ struct option {
 	.short_name = (s), \
 	.long_name = (l), \
 	.value = (v), \
+	.precision = sizeof(*v), \
 	.help = (h), \
 	.flags = PARSE_OPT_NOARG, \
 	.defval = (b), \