checker: fix match expr with if expr (fix #10177 #10178) (#10179)

vlib/v/checker/checker.v

@@ -5326,6 +5326,9 @@ pub fn (mut c Checker) match_expr(mut node ast.MatchExpr) ast.Type {
 			mut stmt := branch.stmts[branch.stmts.len - 1]
 			match mut stmt {
 				ast.ExprStmt {
+					if node.is_expr {
+						c.expected_type = node.expected_type
+					}
 					expr_type := c.expr(stmt.expr)
 					if ret_type == ast.void_type {
 						ret_type = expr_type

vlib/v/checker/tests/if_match_expr.out

@@ -40,3 +40,10 @@ vlib/v/checker/tests/if_match_expr.vv:23:3: error: `match` expression branch has
       |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    24 |         _ = match true {true {1} else {-1}} // OK
    25 |         match true {true {1} else {-1}} // result
+vlib/v/checker/tests/if_match_expr.vv:25:3: error: return type mismatch, it should be `int`
+   23 |         match true {true {} else {}} // statement not expression
+   24 |         _ = match true {true {1} else {-1}} // OK
+   25 |         match true {true {1} else {-1}} // result
+      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+   26 |     }
+   27 | }

vlib/v/gen/c/cgen.v

@@ -1018,6 +1018,7 @@ fn (mut g Gen) stmts_with_tmp_var(stmts []ast.Stmt, tmp_var string) {
 				g.skip_stmt_pos = true
 				g.write('$tmp_var = ')
 				g.stmt(stmt)
+				g.writeln(';')
 			}
 		} else {
 			g.stmt(stmt)

vlib/v/tests/match_expr_with_if_or_match_expr_test.v

@@ -0,0 +1,43 @@
+fn foo1() int {
+	return match 1 {
+		1 {
+			if true {
+				1
+			} else {
+				2
+			}
+		}
+		else {
+			if true {
+				3
+			} else {
+				4
+			}
+		}
+	}
+}
+
+fn foo2() int {
+	return match 1 {
+		1 {
+			match true {
+				true { 1 }
+				false { 2 }
+			}
+		}
+		else {
+			match false {
+				true { 3 }
+				false { 4 }
+			}
+		}
+	}
+}
+
+fn test_match_expr_with_if_or_match_expr() {
+	println(foo1())
+	assert foo1() == 1
+
+	println(foo2())
+	assert foo2() == 1
+}