From 374186f1f77f9d7299a3236d411e611411e4db6c Mon Sep 17 00:00:00 2001
From: yuyi <yuyi98@163.com>
Date: Wed, 17 Aug 2022 13:49:53 +0800
Subject: [PATCH] checker: fix fn call with mut array of aliases arguments
 (#15443)

---
 vlib/v/checker/fn.v                           | 10 +++++--
 .../fn_call_mut_array_of_aliases_args_test.v  | 27 +++++++++++++++++++
 2 files changed, 35 insertions(+), 2 deletions(-)
 create mode 100644 vlib/v/tests/fn_call_mut_array_of_aliases_args_test.v

diff --git a/vlib/v/checker/fn.v b/vlib/v/checker/fn.v
index 1968907ed4..6d9ee4f017 100644
--- a/vlib/v/checker/fn.v
+++ b/vlib/v/checker/fn.v
@@ -958,8 +958,14 @@ pub fn (mut c Checker) fn_call(mut node ast.CallExpr, mut continue_check &bool)
 				param_elem_type := c.table.unaliased_type(param_info.elem_type)
 				arg_info := arg_typ_sym.info as ast.Array
 				arg_elem_type := c.table.unaliased_type(arg_info.elem_type)
-				if param.typ.nr_muls() == arg_typ.nr_muls()
-					&& param_info.nr_dims == arg_info.nr_dims && param_elem_type == arg_elem_type {
+				param_nr_muls := param.typ.nr_muls()
+				arg_nr_muls := if call_arg.is_mut {
+					arg_typ.nr_muls() + 1
+				} else {
+					arg_typ.nr_muls()
+				}
+				if param_nr_muls == arg_nr_muls && param_info.nr_dims == arg_info.nr_dims
+					&& param_elem_type == arg_elem_type {
 					continue
 				}
 			}
diff --git a/vlib/v/tests/fn_call_mut_array_of_aliases_args_test.v b/vlib/v/tests/fn_call_mut_array_of_aliases_args_test.v
new file mode 100644
index 0000000000..27d613d0f5
--- /dev/null
+++ b/vlib/v/tests/fn_call_mut_array_of_aliases_args_test.v
@@ -0,0 +1,27 @@
+fn f1(mut b []byte) string {
+	return '$b'
+}
+
+fn f2(b []byte) string {
+	return '$b'
+}
+
+fn f3(mut b []u8) string {
+	return '$b'
+}
+
+fn test_fn_call_mut_array_of_aliases() {
+	mut s1 := 'test'.bytes()
+
+	ret1 := f1(mut s1)
+	println(ret1)
+	assert ret1 == '[116, 101, 115, 116]'
+
+	ret2 := f2(s1)
+	println(ret2)
+	assert ret2 == '[116, 101, 115, 116]'
+
+	ret3 := f3(mut s1)
+	println(ret3)
+	assert ret3 == '[116, 101, 115, 116]'
+}