ViewDispatches throws NullPointerException on an unresolved receiver type (any unbuilt project, every level) in 3.3.0–3.3.2 #265

Problem

ViewDispatches.siteOf tests DISPATCHER_TYPES.contains(receiver) / RESPONSE_TYPES.contains(receiver) where both sets are Set.of(...), whose contains(null) throws. A call body node's receiver_type is null whenever the receiver did not resolve — an unbuilt project with no target/ and no Maven, a missing jar — so from 3.3.0 any such project with a forward / include / sendRedirect call crashes the whole run at every analysis level: java.lang.RuntimeException: java.lang.NullPointerException: Cannot invoke "Object.equals(Object)" because "<parameter1>" is null at CodeAnalyzer.analyze(CodeAnalyzer.java:261). Found by python-sdk's test_java_degradation.py (a copy of daytrader8 with no target/, -a 4) when the SDK moved its pin to 3.3.2 (python-sdk#404).

Scope boundary

The null guard and its test only. Detection by declared receiver type stays: an unresolved receiver is not a site, and the run degrades as it did before 3.3.0.

Goals

• siteOf returns null for a null receiver type before any set lookup.
• ViewDispatchesTest: a tree with import javax.servlet.http.* and no stubs — every receiver unresolved — yields no dispatches, no unresolved records, and no exception.

Caveats and known risks

• None beyond the obvious: a degraded run reports no dispatches at all, which is the pre-existing condition config reads live with (detection needs the servlet types to resolve).

Definition of done

• The new test fails with the NPE on 3.3.2's code and passes with the guard; the full suite is green; python-sdk's test_java_degradation.py passes against the released patch.