fix12

Author: medvednikov

vlib/v/parser/assign.v

@@ -132,10 +132,12 @@ fn (mut p Parser) check_undefined_variables(names []string, val ast.Expr) ! {
 }
 
 fn (mut p Parser) check_cross_variables(exprs []ast.Expr, val ast.Expr) bool {
-	// NOTE: val_str must be computed before the match, because inside match arms
-	// `val` gets smartcast to the variant type, and calling .str() on e.g.
-	// IndexExpr would call the auto-generated struct str() instead of Expr.str().
-	val_str := val.str()
+	// NOTE: For IndexExpr and SelectorExpr, we need to compare string representations.
+	// val_str must be computed before the match, because inside match arms `val` gets
+	// smartcast to the variant type, and calling .str() on e.g. IndexExpr would call
+	// the auto-generated struct str() instead of Expr.str().
+	// Only compute it for the types that actually need it.
+	val_str := if val is ast.IndexExpr || val is ast.SelectorExpr { val.str() } else { '' }
 	match val {
 		ast.Ident {
 			for expr in exprs {