From 87f4a7f7d4cd8a401128b1947823d9bf109703b3 Mon Sep 17 00:00:00 2001
From: deelawn <dboltz03@gmail.com>
Date: Sun, 17 Dec 2023 10:16:24 +0100
Subject: [PATCH 1/2] boolean operations must have boolean operands

---
 gnovm/pkg/gnolang/preprocess.go | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/gnovm/pkg/gnolang/preprocess.go b/gnovm/pkg/gnolang/preprocess.go
index 1a1edc41222..2e428cfd344 100644
--- a/gnovm/pkg/gnolang/preprocess.go
+++ b/gnovm/pkg/gnolang/preprocess.go
@@ -755,6 +755,13 @@ func Preprocess(store Store, ctx BlockNode, n Node) Node {
 					resn := Preprocess(store, last, n2)
 					return resn, TRANS_CONTINUE
 				}
+
+				// Left and right hand expressions must evaluate to a boolean typed value if
+				// the operation is a logical AND or OR.
+				if (n.Op == LAND || n.Op == LOR) && (lt.Kind() != BoolKind || rt.Kind() != BoolKind) {
+					panic("operands of boolean operators must evaluate to boolean typed values")
+				}
+
 				// General case.
 				lcx, lic := n.Left.(*ConstExpr)
 				rcx, ric := n.Right.(*ConstExpr)

From 207764a20a56c8570d7089d8995d1c85df88fc3a Mon Sep 17 00:00:00 2001
From: deelawn <dboltz03@gmail.com>
Date: Sun, 17 Dec 2023 12:27:33 +0100
Subject: [PATCH 2/2] added tests

---
 gnovm/tests/files/bool6.gno | 12 ++++++++++++
 gnovm/tests/files/bool7.gno | 16 ++++++++++++++++
 2 files changed, 28 insertions(+)
 create mode 100644 gnovm/tests/files/bool6.gno
 create mode 100644 gnovm/tests/files/bool7.gno

diff --git a/gnovm/tests/files/bool6.gno b/gnovm/tests/files/bool6.gno
new file mode 100644
index 00000000000..ad4d832036c
--- /dev/null
+++ b/gnovm/tests/files/bool6.gno
@@ -0,0 +1,12 @@
+package main
+
+func main() {
+	println(X())
+}
+
+func X() string {
+	return "hello" || "world"
+}
+
+// Error:
+// main/files/bool6.gno:8: operands of boolean operators must evaluate to boolean typed values
diff --git a/gnovm/tests/files/bool7.gno b/gnovm/tests/files/bool7.gno
new file mode 100644
index 00000000000..ba8be09dc7c
--- /dev/null
+++ b/gnovm/tests/files/bool7.gno
@@ -0,0 +1,16 @@
+package main
+
+// Ensure, when comparing evaluated boolean operand types, that the kinds produced
+// are the same when one operand is typed and the other is untyped.
+func main() {
+	println(boolAndTrue(true))
+	println(boolAndTrue(false))
+}
+
+func boolAndTrue(b bool) bool {
+	return b && true
+}
+
+// Output:
+// true
+// false