From b0665ea978919a333d029677a75a16a608ae5ab4 Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@medvednikov.com>
Date: Tue, 14 Apr 2026 12:45:37 +0300
Subject: [PATCH] flag: repeated int option in a single argument does not work
 (fixes #25362)

---
 vlib/flag/flag_to.v                | 18 ++++++++++++++++--
 vlib/flag/posix_style_flags_test.v | 26 ++++++++++++++++++++++++++
 2 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/vlib/flag/flag_to.v b/vlib/flag/flag_to.v
index 7821eca0d..b4351b022 100644
--- a/vlib/flag/flag_to.v
+++ b/vlib/flag/flag_to.v
@@ -1433,8 +1433,9 @@ fn (mut fm FlagMapper) map_posix_short_cluster(flag_ctx FlagContext) ! {
 	if flag_name.len <= 1 {
 		return
 	}
-	// Do not handle multiple `-vv`, `map_posix_short` does that
-	if flag_name[0] == flag_name[1] {
+	first_letter := flag_name[0].ascii_str()
+	// Do not handle repeated-only bundles like `-vv`; `map_posix_short` does that.
+	if flag_name.count(first_letter) == flag_name.len {
 		return
 	}
 
@@ -1478,6 +1479,19 @@ fn (mut fm FlagMapper) map_posix_short_cluster(flag_ctx FlagContext) ! {
 						'true', '')}')
 					fm.field_map_flag[mf.field_name] = mf
 					fm.handled_pos << flag_ctx.pos
+				} else if field.hints.has(.can_repeat) {
+					repeats := if existing := fm.field_map_flag[mf.field_name] {
+						existing.repeats + 1
+					} else {
+						1
+					}
+					trace_println('${@FN}: found match for (repeatable cluster) ${fm.dbg_match(flag_ctx,
+						field, '${repeats}', '')}')
+					fm.field_map_flag[mf.field_name] = FlagData{
+						...mf
+						repeats: repeats
+					}
+					fm.handled_pos << flag_ctx.pos
 				} else {
 					mut arg := split[i + 1..].clone().join('')
 					mut next_is_used := false
diff --git a/vlib/flag/posix_style_flags_test.v b/vlib/flag/posix_style_flags_test.v
index 69c44b6dc..71c5ac516 100644
--- a/vlib/flag/posix_style_flags_test.v
+++ b/vlib/flag/posix_style_flags_test.v
@@ -12,6 +12,9 @@ const posix_multi_short_args_2 = ['-vv', 'vvv', '-done', '-d', 'two', '-yxz', '2
 const posix_multi_short_args_3 = ['-vv', 'vvv', '-xyz', '2', '-done', '-d', 'two']
 const posix_multi_short_args_4 = ['-yxz2', '-vv', 'vvv', '-done', '-d', 'two']
 const posix_multi_short_args_1_err = ['-zxy']
+const repeatable_cluster_args_1 = ['-mv']
+const repeatable_cluster_args_2 = ['-vmm']
+const repeatable_cluster_args_3 = ['-mmv']
 
 struct Config {
 	linker_option string   @[short: m]
@@ -25,6 +28,11 @@ struct Config {
 	u             int  @[short: z]
 }
 
+struct RepeatableClusterConfig {
+	show_version bool @[only: v]
+	multi        int  @[only: m; repeats]
+}
+
 fn test_pure_posix_short() {
 	config, _ := flag.to_struct[Config](exe_and_posix_args, skip: 1, style: .short)!
 	assert config.verbosity == 5
@@ -104,6 +112,24 @@ fn test_pure_posix_multi_short_err_1() {
 	}
 }
 
+fn test_pure_posix_short_repeatable_cluster_1() {
+	config, _ := flag.to_struct[RepeatableClusterConfig](repeatable_cluster_args_1, style: .short)!
+	assert config.show_version
+	assert config.multi == 1
+}
+
+fn test_pure_posix_short_repeatable_cluster_2() {
+	config, _ := flag.to_struct[RepeatableClusterConfig](repeatable_cluster_args_2, style: .short)!
+	assert config.show_version
+	assert config.multi == 2
+}
+
+fn test_pure_posix_short_repeatable_cluster_3() {
+	config, _ := flag.to_struct[RepeatableClusterConfig](repeatable_cluster_args_3, style: .short)!
+	assert config.show_version
+	assert config.multi == 2
+}
+
 fn test_pure_posix_short_no_exe() {
 	config, _ := flag.to_struct[Config](exe_and_posix_args[1..], style: .short)!
 	assert config.verbosity == 5
-- 
2.39.5