From 0f251e9edefe6f692dfc2303abc49c0a29908459 Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@medvednikov.com>
Date: Thu, 14 May 2020 18:30:30 +0200
Subject: [PATCH] checker: handle json.decode correctly

---
 vlib/v/checker/checker.v | 4 ++--
 vlib/v/parser/fn.v       | 6 +++---
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/vlib/v/checker/checker.v b/vlib/v/checker/checker.v
index 7a32e1aca5..feed2eb30a 100644
--- a/vlib/v/checker/checker.v
+++ b/vlib/v/checker/checker.v
@@ -935,8 +935,8 @@ pub fn (mut c Checker) check_expr_opt_call(x ast.Expr, xtype table.Type, is_retu
 		ast.CallExpr {
 			if it.return_type.flag_is(.optional) {
 				c.check_or_block(it, xtype, is_return_used)
-			} else if it.or_block.is_used {
-				c.error('unexpected `or` block, the function does not return an optional',
+			} else if it.or_block.is_used && it.name != 'json.decode' { // TODO remove decode hack
+				c.error('unexpected `or` block, the function `$it.name` does not return an optional',
 					it.pos)
 			}
 		}
diff --git a/vlib/v/parser/fn.v b/vlib/v/parser/fn.v
index 4969f03ffd..e1243ba678 100644
--- a/vlib/v/parser/fn.v
+++ b/vlib/v/parser/fn.v
@@ -20,10 +20,11 @@ pub fn (mut p Parser) call_expr(is_c, is_js bool, mod string) ast.CallExpr {
 	} else {
 		name
 	}
+	mut is_or_block_used := false
 	if fn_name == 'json.decode' {
-		// Makes name_expr() parse the type (`User` in `json.decode(User, txt)`)`
-		p.expecting_type = true
+		p.expecting_type = true // Makes name_expr() parse the type (`User` in `json.decode(User, txt)`)`
 		p.expr_mod = ''
+		is_or_block_used = true
 	}
 	p.check(.lpar)
 	args := p.call_args()
@@ -35,7 +36,6 @@ pub fn (mut p Parser) call_expr(is_c, is_js bool, mod string) ast.CallExpr {
 		len: last_pos.pos - first_pos.pos + last_pos.len
 	}
 	mut or_stmts := []ast.Stmt{}
-	mut is_or_block_used := false
 	if p.tok.kind == .key_orelse {
 		p.inside_or_expr = true
 		p.next()