builtin,os: fix windows execute ANSI encoding result, make msvc error messages readable in a Chinese locale (fix #25727) (#25736)

Author: kbkpbot

vlib/builtin/utf8.c.v

@@ -5,6 +5,11 @@ import strings
 const cp_acp = 0
 const cp_utf8 = 65001
 
+@[params]
+pub struct ToWideConfig {
+	from_ansi bool
+}
+
 // to_wide returns a pointer to an UTF-16 version of the string receiver.
 // In V, strings are encoded using UTF-8 internally, but on windows most APIs,
 // that accept strings, need them to be in UTF-16 encoding.
@@ -13,14 +18,16 @@ const cp_utf8 = 65001
 // See also MultiByteToWideChar ( https://learn.microsoft.com/en-us/windows/win32/api/stringapiset/nf-stringapiset-multibytetowidechar )
 // See also builtin.wchar.from_string/1, for a version, that produces a
 // platform dependant L"" C style wchar_t* wide string.
-pub fn (_str string) to_wide() &u16 {
+pub fn (_str string) to_wide(param ToWideConfig) &u16 {
 	$if windows {
 		unsafe {
-			num_chars := (C.MultiByteToWideChar(cp_utf8, 0, &char(_str.str), _str.len,
+			src_encoding := if param.from_ansi { cp_acp } else { cp_utf8 }
+			num_chars := (C.MultiByteToWideChar(src_encoding, 0, &char(_str.str), _str.len,
 				0, 0))
 			mut wstr := &u16(malloc_noscan((num_chars + 1) * 2)) // sizeof(wchar_t)
 			if wstr != 0 {
-				C.MultiByteToWideChar(cp_utf8, 0, &char(_str.str), _str.len, wstr, num_chars)
+				C.MultiByteToWideChar(src_encoding, 0, &char(_str.str), _str.len, wstr,
+					num_chars)
 				C.memset(&u8(wstr) + num_chars * 2, 0, 2)
 			}
 			return wstr

vlib/os/os_windows.c.v

@@ -1,6 +1,7 @@
 module os
 
 import strings
+import encoding.utf8.validate
 
 #flag windows -l advapi32
 #include <process.h>
@@ -387,7 +388,13 @@ pub fn raw_execute(cmd string) Result {
 			break
 		}
 	}
-	soutput := read_data.str()
+	// encoding: from ANSI to UTF-8
+	soutput_str := read_data.str()
+	soutput := if validate.utf8_string(soutput_str) {
+		soutput_str
+	} else {
+		string_from_wide(soutput_str.to_wide(from_ansi: true))
+	}
 	unsafe { read_data.free() }
 	exit_code := u32(0)
 	C.WaitForSingleObject(proc_info.h_process, C.INFINITE)

vlib/v/compiler_errors_test.v

@@ -249,7 +249,6 @@ fn (mut tasks Tasks) run() {
 		m_skip_files << 'vlib/v/checker/tests/comptime_value_d_in_include_errors.vv'
 	}
 	$if msvc {
-		m_skip_files << 'vlib/v/checker/tests/invalid_utf8_string.vv'
 		m_skip_files << 'vlib/v/checker/tests/asm_alias_does_not_exist.vv'
 		m_skip_files << 'vlib/v/checker/tests/asm_immutable_err.vv'
 		// TODO: investigate why MSVC regressed
@@ -258,6 +257,7 @@ fn (mut tasks Tasks) run() {
 		m_skip_files << 'vlib/v/checker/tests/comptime_value_d_in_include_errors.vv'
 	}
 	$if windows {
+		m_skip_files << 'vlib/v/checker/tests/invalid_utf8_string.vv'
 		m_skip_files << 'vlib/v/checker/tests/modules/deprecated_module'
 	}
 	for i in 0 .. tasks.all.len {