Add test for #14509 (#8480)

This was fixed by b599bb4.

Author: ludviggunne

test/testunusedvar.cpp

@@ -249,6 +249,7 @@ class TestUnusedVar : public TestFixture {
         TEST_CASE(localvarDelete);
         TEST_CASE(localvarLambda); // #8941, #8948
         TEST_CASE(localvarStructuredBinding); // #10368
+        TEST_CASE(localvarPtrToPtr);
 
         TEST_CASE(localvarCppInitialization);
         TEST_CASE(localvarCpp11Initialization);
@@ -6958,6 +6959,16 @@ class TestUnusedVar : public TestFixture {
         ASSERT_EQUALS("", errout_str());
     }
 
+    void localvarPtrToPtr() {
+        functionVariableUsage("int main() {\n"
+                              "  int *p, **pp = &p;\n"
+                              "  int i = 123;\n"
+                              "  *pp = &i;\n"
+                              "  return *p;\n"
+                              "}\n");
+        ASSERT_EQUALS("", errout_str());
+    }
+
     void localvarCppInitialization() {
         functionVariableUsage("void foo() {\n"
                               "    int buf[6];\n"