Do not ignore composite meter filters child meter filters

micrometer-core/src/main/java/io/micrometer/core/instrument/MeterRegistry.java

@@ -849,6 +849,24 @@ public Config pauseDetector(PauseDetector detector) {
             return this;
         }
 
+        MeterFilter[] getFilters() {
+            return filters;
+        }
+
+        /**
+         * Merges the provided configuration with this one.
+         * @param config configuration to merge
+         * @return this configuration with merged elements from the provided configuration
+         * @since 1.9.18
+         */
+        public Config merge(Config config) {
+            for (MeterFilter filter : config.getFilters()) {
+                meterFilter(filter);
+            }
+            // TODO: What else should we merge?
+            return this;
+        }
+
         /**
          * @return The pause detector that is currently in effect.
          */

micrometer-core/src/main/java/io/micrometer/core/instrument/composite/CompositeMeterRegistry.java

@@ -227,6 +227,13 @@ private void updateDescendants() {
 
         nonCompositeDescendants = descendants;
 
+        for (MeterRegistry nonCompositeDescendant : nonCompositeDescendants) {
+            Config config = nonCompositeDescendant.config();
+            if (config != null) { // for tests
+                config.merge(config());
+            }
+        }
+
         lock(parentLock, () -> parents.forEach(CompositeMeterRegistry::updateDescendants));
     }
 

micrometer-core/src/test/java/io/micrometer/core/instrument/composite/CompositeMeterRegistryTest.java

@@ -44,8 +44,7 @@
 import static java.util.Collections.singletonList;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.*;
 
 /**
  * Tests for {@link CompositeMeterRegistry}.
@@ -493,4 +492,24 @@ void meterRemovalPropagatesToChildRegistryWithModifyingFilter() {
         assertThat(this.simple.getMeters()).isEmpty();
     }
 
+    @Test
+    void filtersOnIntermediateCompositeMeterRegistryShouldWork() {
+        CompositeMeterRegistry parentMeterRegistry = new CompositeMeterRegistry();
+
+        CompositeMeterRegistry intermediateMeterRegistry = new CompositeMeterRegistry();
+        intermediateMeterRegistry.config().meterFilter(MeterFilter.denyNameStartsWith("deny"));
+        parentMeterRegistry.add(intermediateMeterRegistry);
+
+        SimpleMeterRegistry leafMeterRegistry = new SimpleMeterRegistry();
+        intermediateMeterRegistry.add(leafMeterRegistry);
+
+        parentMeterRegistry.counter("deny.item");
+
+        assertThat(parentMeterRegistry.getMeters()).hasSize(1);
+        // This seems to be empty with and without the filter.
+        assertThat(intermediateMeterRegistry.getMeters()).isEmpty();
+        // Filters on intermediate composite meter registries don't seem to work.
+        assertThat(leafMeterRegistry.getMeters()).isEmpty();
+    }
+
 }