From 3a212f17d82483ff0997848c34ab581fea189f3d Mon Sep 17 00:00:00 2001
From: chrchr-github <78114321+chrchr-github@users.noreply.github.com>
Date: Wed, 17 Apr 2024 11:43:08 +0200
Subject: [PATCH] Fix #12620 Crash in checkReturnByReference() (#6300)

---
 lib/checkclass.cpp | 2 +-
 test/testclass.cpp | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/lib/checkclass.cpp b/lib/checkclass.cpp
index 7dc6c3f1468..018b700104b 100644
--- a/lib/checkclass.cpp
+++ b/lib/checkclass.cpp
@@ -3306,7 +3306,7 @@ void CheckClass::checkUselessOverride()
 }
 
 static const Variable* getSingleReturnVar(const Scope* scope) {
-    if (!scope)
+    if (!scope || !scope->bodyStart)
         return nullptr;
     const Token* const start = scope->bodyStart->next();
     const Token* const end = Token::findsimplematch(start, ";", 1, scope->bodyEnd);
diff --git a/test/testclass.cpp b/test/testclass.cpp
index c9dde77fae5..6f37f0c3c92 100644
--- a/test/testclass.cpp
+++ b/test/testclass.cpp
@@ -8951,6 +8951,10 @@ class TestClass : public TestFixture {
                                "    std::string f(std::string s) { return s; }\n"
                                "};\n");
         ASSERT_EQUALS("", errout_str());
+
+        checkReturnByReference("struct S { S(); };\n" // #12620
+                               "S::S() = delete;\n");
+        ASSERT_EQUALS("", errout_str()); // don't crash
     }
 };