Add test

Author: ludviggunne

test/testunusedvar.cpp

@@ -271,6 +271,8 @@ class TestUnusedVar : public TestFixture {
         TEST_CASE(globalData);
 
         TEST_CASE(structuredBinding); // #13269
+
+        TEST_CASE(pointerCast); // #14535
     }
 
     struct FunctionVariableUsageOptions
@@ -7308,6 +7310,15 @@ class TestUnusedVar : public TestFixture {
                               "}\n");
         ASSERT_EQUALS("", errout_str());
     }
+
+    void pointerCast() { // #14535
+        functionVariableUsage("void f(int* p)\n"
+                              "{\n"
+                              "    int* p2 = p;\n"
+                              "    ((int *)(p2))[0] = 0; // remove cast for warning to disappear\n"
+                              "}\n");
+        ASSERT_EQUALS("", errout_str());
+    }
 };
 
 REGISTER_TEST(TestUnusedVar)