…c filter is set (operator-framework#3518)

`acceptedByFiler` guards each of its three filter branches with
`onXFilter != null || genericFilter != null`, but the branch body
dereferences `onXFilter` unconditionally:

    if (onAddFilter != null || genericFilter != null) {
      ... .anyMatch(r -> acceptedByGenericFiler(r) && onAddFilter.accept(r));

So configuring only a generic filter via `setGenericFilter(...)` throws a
NullPointerException as soon as a resource is added, deleted or updated.
All three branches (add / delete / update) are affected, which means
`PollingEventSource`, `PerResourcePollingEventSource` and
`CachingInboundEventSource` all break when used with a generic filter
only.

The existing `genericFilteringEvents` test missed this because it uses a
filter that returns `false`: `&&` short-circuits before the null
dereference. Only a generic filter that accepts a resource reaches the
NPE.

Each filter check is now null-safe (an absent filter accepts), which
preserves the previous behaviour whenever the specific filter is set.

Adds three regression tests, one per branch; they fail with
NullPointerException without this change.

Signed-off-by: Attila Mészáros <a_meszaros@apple.com>
# Conflicts:
#	operator-framework-core/src/test/java/io/javaoperatorsdk/operator/processing/event/source/ExternalResourceCachingEventSourceTest.java

…c filter is set (operator-framework#3518)

`acceptedByFiler` guards each of its three filter branches with
`onXFilter != null || genericFilter != null`, but the branch body
dereferences `onXFilter` unconditionally:

    if (onAddFilter != null || genericFilter != null) {
      ... .anyMatch(r -> acceptedByGenericFiler(r) && onAddFilter.accept(r));

So configuring only a generic filter via `setGenericFilter(...)` throws a
NullPointerException as soon as a resource is added, deleted or updated.
All three branches (add / delete / update) are affected, which means
`PollingEventSource`, `PerResourcePollingEventSource` and
`CachingInboundEventSource` all break when used with a generic filter
only.

The existing `genericFilteringEvents` test missed this because it uses a
filter that returns `false`: `&&` short-circuits before the null
dereference. Only a generic filter that accepts a resource reaches the
NPE.

Each filter check is now null-safe (an absent filter accepts), which
preserves the previous behaviour whenever the specific filter is set.

Adds three regression tests, one per branch; they fail with
NullPointerException without this change.

Signed-off-by: Attila Mészáros <a_meszaros@apple.com>
# Conflicts:
#	operator-framework-core/src/test/java/io/javaoperatorsdk/operator/processing/event/source/ExternalResourceCachingEventSourceTest.java

…3524)

* fix: read the external resource cache under the event source monitor

`ExternalResourceCachingEventSource` mutates its cache from `synchronized`
methods (`handleResources`, `handleDelete`,
`handleRecentResourceCreate/Update`), but the read paths were not
synchronized. The outer map is a `ConcurrentHashMap`; the nested
per-primary maps are plain `HashMap`s that `handleDelete` mutates in
place, so a reconciler thread reading them while a poll or informer
thread writes can observe a corrupted map or throw.

`getSecondaryResources(ResourceID)` additionally looked the primary up
twice:

    var cachedValues = cache.get(primaryID);
    if (cachedValues == null) { return Collections.emptySet(); }
    else { return new HashSet<>(cache.get(primaryID).values()); }

If a concurrent `handleDelete` removes the entry between the two calls,
the second `get` returns null and this throws a NullPointerException.

Adds a `cachedResourcesFor` helper that snapshots the cached resources
while holding the monitor, and routes `getSecondaryResources` plus the
`PerResourcePollingEventSource` and `CachingInboundEventSource` overrides
(and `checkAndRegisterTask`) through it. The helper only copies, so the
potentially slow `ResourceFetcher` calls in those overrides still run
outside the lock and cannot block the informer or poll threads.

`getCache()` still returns a live view for backwards compatibility, but
now documents that iterating the nested maps requires synchronizing on the
event source.

Adds a test asserting `getSecondaryResources` returns a snapshot rather
than a live view.

* fix: NPE in external resource caching event source when only a generic filter is set (#3518)

`acceptedByFiler` guards each of its three filter branches with
`onXFilter != null || genericFilter != null`, but the branch body
dereferences `onXFilter` unconditionally:

    if (onAddFilter != null || genericFilter != null) {
      ... .anyMatch(r -> acceptedByGenericFiler(r) && onAddFilter.accept(r));

So configuring only a generic filter via `setGenericFilter(...)` throws a
NullPointerException as soon as a resource is added, deleted or updated.
All three branches (add / delete / update) are affected, which means
`PollingEventSource`, `PerResourcePollingEventSource` and
`CachingInboundEventSource` all break when used with a generic filter
only.

The existing `genericFilteringEvents` test missed this because it uses a
filter that returns `false`: `&&` short-circuits before the null
dereference. Only a generic filter that accepts a resource reaches the
NPE.

Each filter check is now null-safe (an absent filter accepts), which
preserves the previous behaviour whenever the specific filter is set.

Adds three regression tests, one per branch; they fail with
NullPointerException without this change.

Signed-off-by: Attila Mészáros <a_meszaros@apple.com>
# Conflicts:
#	operator-framework-core/src/test/java/io/javaoperatorsdk/operator/processing/event/source/ExternalResourceCachingEventSourceTest.java

---------

Signed-off-by: Attila Mészáros <a_meszaros@apple.com>