cgen: fix optional generation order (#11070)

vlib/v/gen/c/cgen.v

@@ -3280,6 +3280,7 @@ fn (mut g Gen) expr(node ast.Expr) {
 					g.writeln('($shared_styp*)__dup${shared_styp}(&($shared_styp){.mtx = {0}, .val =')
 				}
 			}
+			last_stmt_pos := g.stmt_path_pos.last()
 			g.call_expr(node)
 			// if g.fileis('1.strings') {
 			// println('before:' + node.autofree_pregen)
@@ -3291,7 +3292,7 @@ fn (mut g Gen) expr(node ast.Expr) {
 				// so just skip it
 				g.autofree_call_pregen(node)
 				if g.strs_to_free0.len > 0 {
-					g.insert_before_stmt(g.strs_to_free0.join('\n') + '/* inserted before */')
+					g.insert_at(last_stmt_pos, g.strs_to_free0.join('\n') + '/* inserted before */')
 				}
 				g.strs_to_free0 = []
 				// println('pos=$node.pos.pos')
@@ -5840,6 +5841,12 @@ fn (mut g Gen) insert_before_stmt(s string) {
 	g.write(cur_line)
 }
 
+fn (mut g Gen) insert_at(pos int, s string) {
+	cur_line := g.out.cut_to(pos)
+	g.writeln(s)
+	g.write(cur_line)
+}
+
 // fn (mut g Gen) start_tmp() {
 // }
 // If user is accessing the return value eg. in assigment, pass the variable name.
@@ -5925,6 +5932,7 @@ fn (mut g Gen) or_block(var_name string, or_block ast.OrExpr, return_type ast.Ty
 		}
 	}
 	g.writeln('}')
+	g.stmt_path_pos << g.out.len
 }
 
 [inline]

vlib/v/tests/option_struct_init_test.v

@@ -0,0 +1,22 @@
+struct Foo {
+	a int
+	b int
+	c int
+}
+
+struct Holder {
+mut:
+	i int
+}
+
+fn add(mut h Holder) ?int {
+	h.i++
+	return h.i
+}
+
+fn test_struct_init_with_multiple_optionals() {
+	mut h := Holder{}
+	foo := Foo{add(mut h) or { 0 }, add(mut h) or { 0 }, add(mut h) or { 0 }}
+
+	assert foo == Foo{1, 2, 3}
+}