C++: Add failing test.

Author: MathiasVP

cpp/ql/test/library-tests/dataflow/dataflow-tests/dataflow-consistency.expected

@@ -128,6 +128,7 @@ postWithInFlow
 | test.cpp:690:3:690:3 | s [post update] | PostUpdateNode should not be the target of local flow. |
 | test.cpp:694:4:694:6 | buf [inner post update] | PostUpdateNode should not be the target of local flow. |
 | test.cpp:704:23:704:25 | buf [inner post update] | PostUpdateNode should not be the target of local flow. |
+| test.cpp:715:25:715:25 | c [inner post update] | PostUpdateNode should not be the target of local flow. |
 viableImplInCallContextTooLarge
 uniqueParameterNodeAtPosition
 uniqueParameterNodePosition

cpp/ql/test/library-tests/dataflow/dataflow-tests/test.cpp

@@ -702,4 +702,21 @@ void call_increment_buf(int** buf) { // $ ast-def=buf
 void test_conflation_regression(int* source) { // $ ast-def=source
   int* buf = source;
   call_increment_buf(&buf);
+}
+
+void write_to_star_star_p(unsigned char **p) // $ ast-def=p ir-def=**p ir-def=*p
+{
+  **p = 0;
+}
+
+void write_to_star_buf(unsigned char *buf) // $ ast-def=buf
+{
+  unsigned char *c = buf;
+  write_to_star_star_p(&c);
+}
+
+void test(unsigned char *source) // $ ast-def=source
+{
+  write_to_star_buf(source);
+  sink(*source); // $ SPURIOUS: ir
 }