Fix #14231 Crash in checkConstVariable() (#7931)

Co-authored-by: chrchr-github <noreply@github.com>

Author: chrchr-github

lib/checkother.cpp

@@ -1723,7 +1723,7 @@ void CheckOther::checkConstVariable()
                 if (retTok->varId() == var->declarationId())
                     return true;
                 while (retTok && retTok->isCast())
-                    retTok = retTok->astOperand2();
+                    retTok = retTok->astOperand2() ? retTok->astOperand2() : retTok->astOperand1();
                 while (Token::simpleMatch(retTok, "."))
                     retTok = retTok->astOperand2();
                 if (Token::simpleMatch(retTok, "&"))

test/testother.cpp

@@ -3967,6 +3967,13 @@ class TestOther : public TestFixture {
 
         check("size_t* f(std::array<uint8_t, 128>& a) { return reinterpret_cast<size_t*>(a.data()); }\n"); // #14074
         ASSERT_EQUALS("", errout_str());
+
+        check("struct S { int i; };\n" // #14231
+              "void* f(S& s, int& v) {\n"
+              "    v = s.i;\n"
+              "    return (void*)&s;\n"
+              "}\n"); // don't crash
+        ASSERT_EQUALS("", errout_str());
     }
 
     void constParameterCallback() {