From 1b9417220971f271daaf2d4cc7e2a41d34edaeb0 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sat, 16 Oct 2021 16:49:44 +0300
Subject: [PATCH] Save possible outer reference when entering subscript

Otherwise it gets corrupted and the outer variable may be incorrectly
removed if nothing else refers to it.
---
 source/glsl/optimize.cpp             |  1 +
 tests/glsl/nested_member_access.glsl | 46 ++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+)
 create mode 100644 tests/glsl/nested_member_access.glsl

diff --git a/source/glsl/optimize.cpp b/source/glsl/optimize.cpp
index 1e974c9f..08d92599 100644
--- a/source/glsl/optimize.cpp
+++ b/source/glsl/optimize.cpp
@@ -1384,6 +1384,7 @@ void UnusedVariableRemover::visit(BinaryExpression &binary)
 		{
 			SetFlag clear_assignment(assignment_target, false);
 			SetFlag clear_composite(composite_reference, false);
+			SetForScope<Assignment::Target> clear_reference(r_reference, Assignment::Target());
 			binary.right->visit(*this);
 		}
 
diff --git a/tests/glsl/nested_member_access.glsl b/tests/glsl/nested_member_access.glsl
new file mode 100644
index 00000000..60b3a492
--- /dev/null
+++ b/tests/glsl/nested_member_access.glsl
@@ -0,0 +1,46 @@
+uniform Lighting
+{
+	vec3 light_color[4];
+};
+uniform Params
+{
+	int light_index;
+};
+
+#pragma MSP stage(vertex)
+layout(location=0) in vec4 position;
+void main()
+{
+	gl_Position = position;
+}
+
+#pragma MSP stage(fragment)
+layout(location=0) out vec4 frag_color;
+void main()
+{
+	frag_color = vec4(light_color[light_index], 1.0);
+}
+
+/* Expected output: vertex
+layout(location=0) in vec4 position;
+void main()
+{
+	gl_Position = position;
+}
+*/
+
+/* Expected output: fragment
+layout(binding=5) uniform Lighting
+{
+	vec3 light_color[4];
+};
+layout(binding=80) uniform Params
+{
+	int light_index;
+};
+layout(location=0) out vec4 frag_color;
+void main()
+{
+	frag_color = vec4(light_color[light_index], 1.0);
+}
+*/
-- 
2.43.0