From 8c92e3d0c5e768afc9938bc661fbdd47b36b02f8 Mon Sep 17 00:00:00 2001
From: Delyan Angelov <delian66@gmail.com>
Date: Fri, 14 Mar 2025 07:01:55 +0200
Subject: [PATCH] v.markused: improve stability (avoid runtime crash) when
 processing generic functions (partial fix for #23927)

---
 vlib/v/markused/walker.v | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/vlib/v/markused/walker.v b/vlib/v/markused/walker.v
index 3cbe99bb55..b9d67c9e29 100644
--- a/vlib/v/markused/walker.v
+++ b/vlib/v/markused/walker.v
@@ -599,6 +599,9 @@ pub fn (mut w Walker) a_struct_info(sname string, info ast.Struct) {
 }
 
 pub fn (mut w Walker) fn_decl(mut node ast.FnDecl) {
+	if node == unsafe { nil } {
+		return
+	}
 	if node.language == .c {
 		w.mark_fn_as_used(node.fkey())
 		return
@@ -616,6 +619,9 @@ pub fn (mut w Walker) fn_decl(mut node ast.FnDecl) {
 }
 
 pub fn (mut w Walker) call_expr(mut node ast.CallExpr) {
+	if node == unsafe { nil } {
+		return
+	}
 	for arg in node.args {
 		w.expr(arg.expr)
 	}