From f9334c8340ff4b76b30a9362ced0038e97094256 Mon Sep 17 00:00:00 2001
From: Swastik Baranwal <swstkbaranwal@gmail.com>
Date: Tue, 19 Sep 2023 16:29:57 +0530
Subject: [PATCH] checker: disallow assigning pointer values to option struct
 fields (#19380)

---
 vlib/v/checker/struct.v                         |  4 ++++
 .../struct_option_field_assign_ptr_err.out      | 14 ++++++++++++++
 .../tests/struct_option_field_assign_ptr_err.vv | 17 +++++++++++++++++
 3 files changed, 35 insertions(+)
 create mode 100644 vlib/v/checker/tests/struct_option_field_assign_ptr_err.out
 create mode 100644 vlib/v/checker/tests/struct_option_field_assign_ptr_err.vv

diff --git a/vlib/v/checker/struct.v b/vlib/v/checker/struct.v
index dea608642..8c0185163 100644
--- a/vlib/v/checker/struct.v
+++ b/vlib/v/checker/struct.v
@@ -566,6 +566,10 @@ fn (mut c Checker) struct_init(mut node ast.StructInit, is_field_zero_struct_ini
 							init_field.pos)
 					}
 				}
+				if exp_type.has_flag(.option) && got_type.is_ptr() && !(exp_type.is_ptr()
+					&& exp_type_sym.kind == .struct_) {
+					c.error('cannot assign a pointer to option struct field', init_field.pos)
+				}
 				if exp_type_sym.kind == .voidptr && got_type_sym.kind == .struct_
 					&& !got_type.is_ptr() {
 					c.error('allocate on the heap for use in other functions', init_field.pos)
diff --git a/vlib/v/checker/tests/struct_option_field_assign_ptr_err.out b/vlib/v/checker/tests/struct_option_field_assign_ptr_err.out
new file mode 100644
index 000000000..c20705b62
--- /dev/null
+++ b/vlib/v/checker/tests/struct_option_field_assign_ptr_err.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/struct_option_field_assign_ptr_err.vv:10:3: error: cannot assign a pointer to option struct field
+    8 |     name := 'Bilbo'
+    9 |     a := Abc{
+   10 |         age: &age
+      |         ~~~~~~
+   11 |     }
+   12 |     b := Abc{
+vlib/v/checker/tests/struct_option_field_assign_ptr_err.vv:13:3: error: cannot assign a pointer to option struct field
+   11 |     }
+   12 |     b := Abc{
+   13 |         name: &name
+      |         ~~~~~~~
+   14 |     }
+   15 |     dump(a)
diff --git a/vlib/v/checker/tests/struct_option_field_assign_ptr_err.vv b/vlib/v/checker/tests/struct_option_field_assign_ptr_err.vv
new file mode 100644
index 000000000..43a73c19d
--- /dev/null
+++ b/vlib/v/checker/tests/struct_option_field_assign_ptr_err.vv
@@ -0,0 +1,17 @@
+struct Abc {
+	name ?string
+	age  ?int
+}
+
+fn main() {
+	age := 34
+	name := 'Bilbo'
+	a := Abc{
+		age: &age
+	}
+	b := Abc{
+		name: &name
+	}
+	dump(a)
+	dump(b)
+}
-- 
2.39.5