From b4339f8d50e1ed03c54114c6af20cff8d153a108 Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@medvednikov.com>
Date: Mon, 4 May 2026 09:31:57 +0300
Subject: [PATCH] json2: decode fixes

---
 vlib/builtin/builtin_windows.c.v |  4 ++--
 vlib/x/json2/decode.v            | 33 +++++++++++++++++++++++++-------
 2 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/vlib/builtin/builtin_windows.c.v b/vlib/builtin/builtin_windows.c.v
index a86863200..f8beca2b5 100644
--- a/vlib/builtin/builtin_windows.c.v
+++ b/vlib/builtin/builtin_windows.c.v
@@ -46,7 +46,7 @@ pub type C.LPTSTR = &C.TCHAR
 
 pub type C.LPCTSTR = &C.TCHAR
 
-fn C.WriteConsoleW(voidptr, &u16, u32, &u32, voidptr) bool
+fn C.WriteConsoleW(voidptr, &u16, u32, voidptr, voidptr) bool
 
 fn C._setmode(int, int) int
 
@@ -105,7 +105,7 @@ fn write_buf_to_console(fd int, buf &u8, buf_len int) bool {
 		mut wide_ptr := wide_buf
 		for remaining_chars > 0 {
 			mut chars_written := u32(0)
-			if !C.WriteConsoleW(console_handle, wide_ptr, u32(remaining_chars), &chars_written, nil)
+			if !C.WriteConsoleW(console_handle, wide_ptr, u32(remaining_chars), voidptr(&chars_written), nil)
 				|| chars_written == 0 {
 				return false
 			}
diff --git a/vlib/x/json2/decode.v b/vlib/x/json2/decode.v
index 13303b27f..dd38fd056 100644
--- a/vlib/x/json2/decode.v
+++ b/vlib/x/json2/decode.v
@@ -1219,17 +1219,36 @@ fn (mut decoder Decoder) decode_map[V](mut val map[string]V) ! {
 					decoder.decode_value(mut map_value)!
 				}
 
-				$if V.unaliased_typ is $map {
-					// V is itself a map (alias) - skip assignment to avoid V compiler
-					// confusion about element type of nested map aliases.
+				$if V is $alias && V.unaliased_typ is $map {
+					// V is a map alias (e.g. `type SyntaxStyle = map[string]X`).
+					// V's checker reports `val[key]` as the unaliased element type
+					// while `map_value` keeps the alias type, so direct assignment
+					// fails to type-check. Skip to keep generic instantiations
+					// compilable; decoding into map-alias map values is unsupported.
 				} $else $if K is string {
-					val[key_str] = map_value
+					$if V is $map {
+						val[key_str] = map_value.move()
+					} $else {
+						val[key_str] = map_value
+					}
 				} $else $if K is rune {
-					val[rune(key_str.int())] = map_value
+					$if V is $map {
+						val[rune(key_str.int())] = map_value.move()
+					} $else {
+						val[rune(key_str.int())] = map_value
+					}
 				} $else $if K is $int {
-					val[K(key_str.int())] = map_value
+					$if V is $map {
+						val[K(key_str.int())] = map_value.move()
+					} $else {
+						val[K(key_str.int())] = map_value
+					}
 				} $else {
-					val[key_str] = map_value
+					$if V is $map {
+						val[key_str] = map_value.move()
+					} $else {
+						val[key_str] = map_value
+					}
 				}
 			}
 		} else {
-- 
2.39.5