From b0e7ddfd976e0796dd550f0353e9dd3fd0489480 Mon Sep 17 00:00:00 2001
From: ChAoS_UnItY <minecraft.kyle.train@gmail.com>
Date: Fri, 26 Aug 2022 12:08:57 +0800
Subject: [PATCH] checker: fix non-bool check on use of result bool (fix
 #15539) (#15540)

---
 vlib/v/checker/if.v                           |  4 ++--
 vlib/v/checker/tests/if_expr_optional_err.out | 10 +++++-----
 vlib/v/checker/tests/if_expr_optional_err.vv  |  1 -
 vlib/v/checker/tests/if_expr_result_err.out   |  7 +++++++
 vlib/v/checker/tests/if_expr_result_err.vv    |  9 +++++++++
 5 files changed, 23 insertions(+), 8 deletions(-)
 create mode 100644 vlib/v/checker/tests/if_expr_result_err.out
 create mode 100644 vlib/v/checker/tests/if_expr_result_err.vv

diff --git a/vlib/v/checker/if.v b/vlib/v/checker/if.v
index 473ebaf3e..f3287636b 100644
--- a/vlib/v/checker/if.v
+++ b/vlib/v/checker/if.v
@@ -47,8 +47,8 @@ pub fn (mut c Checker) if_expr(mut node ast.IfExpr) ast.Type {
 				// check condition type is boolean
 				c.expected_type = ast.bool_type
 				cond_typ := c.unwrap_generic(c.expr(branch.cond))
-				if (cond_typ.idx() != ast.bool_type_idx || cond_typ.has_flag(.optional))
-					&& !c.pref.translated && !c.file.is_translated {
+				if (cond_typ.idx() != ast.bool_type_idx || cond_typ.has_flag(.optional)
+					|| cond_typ.has_flag(.result)) && !c.pref.translated && !c.file.is_translated {
 					c.error('non-bool type `${c.table.type_to_str(cond_typ)}` used as if condition',
 						branch.cond.pos())
 				}
diff --git a/vlib/v/checker/tests/if_expr_optional_err.out b/vlib/v/checker/tests/if_expr_optional_err.out
index 9adbc4a24..9df929bfc 100644
--- a/vlib/v/checker/tests/if_expr_optional_err.out
+++ b/vlib/v/checker/tests/if_expr_optional_err.out
@@ -1,7 +1,7 @@
-vlib/v/checker/tests/if_expr_optional_err.vv:7:5: error: non-bool type `?bool` used as if condition
+vlib/v/checker/tests/if_expr_optional_err.vv:6:5: error: non-bool type `?bool` used as if condition
+    4 |
     5 | fn main() {
-    6 | 
-    7 |     if get_bool() {
+    6 |     if get_bool() {
       |        ~~~~~~~~~~
-    8 |         println("Using plain lists")
-    9 |     }
+    7 |         println("Using plain lists")
+    8 |     }
\ No newline at end of file
diff --git a/vlib/v/checker/tests/if_expr_optional_err.vv b/vlib/v/checker/tests/if_expr_optional_err.vv
index 88d617d43..432e4bb7b 100644
--- a/vlib/v/checker/tests/if_expr_optional_err.vv
+++ b/vlib/v/checker/tests/if_expr_optional_err.vv
@@ -3,7 +3,6 @@ fn get_bool() ?bool {
 }
 
 fn main() {
-
 	if get_bool() {
 		println("Using plain lists")
 	}
diff --git a/vlib/v/checker/tests/if_expr_result_err.out b/vlib/v/checker/tests/if_expr_result_err.out
new file mode 100644
index 000000000..c67e1f8c0
--- /dev/null
+++ b/vlib/v/checker/tests/if_expr_result_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/if_expr_result_err.vv:6:5: error: non-bool type `!bool` used as if condition
+    4 |
+    5 | fn main() {
+    6 |     if get_bool() {
+      |        ~~~~~~~~~~
+    7 |         println("Using plain lists")
+    8 |     }
\ No newline at end of file
diff --git a/vlib/v/checker/tests/if_expr_result_err.vv b/vlib/v/checker/tests/if_expr_result_err.vv
new file mode 100644
index 000000000..1dcce464f
--- /dev/null
+++ b/vlib/v/checker/tests/if_expr_result_err.vv
@@ -0,0 +1,9 @@
+fn get_bool() !bool {
+	return true
+}
+
+fn main() {
+	if get_bool() {
+		println("Using plain lists")
+	}
+}
-- 
2.30.2