Fix NPE in DatabaseClientDecorator when JDBC connection has no db type (#12371)

Fix NPE in DatabaseClientDecorator when JDBC connection has no db type

processDatabaseType/dbService dereferenced the NamingEntry returned by
CACHE.computeIfAbsent(dbType, NamingEntry::new) without checking for
null. FixedSizeCache.computeIfAbsent returns null for a null key
without invoking the producer, so a null dbType() (e.g. an
undetermined DBInfo.getType()) led to a NullPointerException in
tracing instrumentation instead of a graceful no-op.

Guard on dbType == null directly instead of inferring it from the
cache's return value, and add a test exercising both methods with a
null dbType.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Merge branch 'master' into dougqh/fix-database-client-decorator-npe

Merge branch 'master' into dougqh/fix-database-client-decorator-npe

Merge branch 'master' into dougqh/fix-database-client-decorator-npe

Co-authored-by: devflow.devflow-routing-intake <devflow.devflow-routing-intake@kubernetes.us1.ddbuild.io>

Author: 2 people

dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/instrumentation/decorator/DatabaseClientDecorator.java

@@ -96,8 +96,10 @@ public String dbService(final String dbType, final String instanceName) {
     if (instanceName != null && Config.get().isDbClientSplitByInstance()) {
       return dbClientService(instanceName);
     }
-    final NamingEntry entry = CACHE.computeIfAbsent(dbType, NamingEntry::new);
-    return entry.getService();
+    if (dbType == null) {
+      return null;
+    }
+    return CACHE.computeIfAbsent(dbType, NamingEntry::new).getService();
   }
 
   public String dbClientService(final String instanceName) {
@@ -144,11 +146,15 @@ public void onRawStatement(AgentSpan span, String sql) {
   }
 
   protected void processDatabaseType(AgentSpan span, String dbType) {
+    if (dbType == null) {
+      return;
+    }
+
     final NamingEntry namingEntry = CACHE.computeIfAbsent(dbType, NamingEntry::new);
     span.setTag(DB_TYPE, namingEntry.dbType);
     postProcessServiceAndOperationName(span, namingEntry);
 
-    if (Config.get().isAppSecRaspEnabled() && dbType != null) {
+    if (Config.get().isAppSecRaspEnabled()) {
       BiConsumer<RequestContext, String> connectDbCallback =
           AgentTracer.get()
               .getCallbackProvider(RequestContextSlot.APPSEC)

dd-java-agent/agent-bootstrap/src/test/java/datadog/trace/bootstrap/instrumentation/decorator/DatabaseClientDecoratorNullDbTypeTest.java

@@ -0,0 +1,70 @@
+package datadog.trace.bootstrap.instrumentation.decorator;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+
+import datadog.trace.bootstrap.instrumentation.api.AgentSpan;
+import org.junit.jupiter.api.Test;
+
+class DatabaseClientDecoratorNullDbTypeTest {
+
+  private final AgentSpan span = mock(AgentSpan.class);
+  private final DatabaseClientDecorator<Object> decorator =
+      new DatabaseClientDecorator<Object>() {
+        @Override
+        protected String[] instrumentationNames() {
+          return new String[] {"test"};
+        }
+
+        @Override
+        protected CharSequence spanType() {
+          return "test-type";
+        }
+
+        @Override
+        protected CharSequence component() {
+          return "test-component";
+        }
+
+        @Override
+        protected String service() {
+          return "test-service";
+        }
+
+        @Override
+        protected String dbType() {
+          return null;
+        }
+
+        @Override
+        protected String dbUser(Object connection) {
+          return null;
+        }
+
+        @Override
+        protected String dbInstance(Object connection) {
+          return null;
+        }
+
+        @Override
+        protected CharSequence dbHostname(Object connection) {
+          return null;
+        }
+      };
+
+  @Test
+  void processDatabaseTypeWithNullDbTypeDoesNotThrowOrTag() {
+    assertDoesNotThrow(() -> decorator.processDatabaseType(span, null));
+
+    verify(span, never()).setTag(anyString(), anyString());
+  }
+
+  @Test
+  void dbServiceWithNullDbTypeReturnsNull() {
+    assertNull(decorator.dbService(null, null));
+  }
+}