Fix Null pointer exception on passing empty search attribute (#2277)

Author: Quinn-With-Two-Ns

temporal-sdk/src/main/java/io/temporal/internal/client/WorkflowClientRequestFactory.java

@@ -132,7 +132,8 @@ StartWorkflowExecutionRequest.Builder newStartWorkflowExecutionRequest(
             "Cannot have search attributes and typed search attributes");
       }
       request.setSearchAttributes(SearchAttributesUtil.encode(options.getSearchAttributes()));
-    } else if (options.getTypedSearchAttributes() != null) {
+    } else if (options.getTypedSearchAttributes() != null
+        && options.getTypedSearchAttributes().size() > 0) {
       request.setSearchAttributes(
           SearchAttributesUtil.encodeTyped(options.getTypedSearchAttributes()));
     }

temporal-sdk/src/main/java/io/temporal/internal/sync/SyncWorkflowContext.java

@@ -865,7 +865,8 @@ private StartChildWorkflowExecutionParameters createChildWorkflowParameters(
             "Cannot have both typed search attributes and search attributes");
       }
       attributes.setSearchAttributes(SearchAttributesUtil.encode(searchAttributes));
-    } else if (options.getTypedSearchAttributes() != null) {
+    } else if (options.getTypedSearchAttributes() != null
+        && options.getTypedSearchAttributes().size() > 0) {
       attributes.setSearchAttributes(
           SearchAttributesUtil.encodeTyped(options.getTypedSearchAttributes()));
     }
@@ -1261,7 +1262,8 @@ public void continueAsNew(ContinueAsNewInput input) {
               "Cannot have typed search attributes and search attributes");
         }
         attributes.setSearchAttributes(SearchAttributesUtil.encode(searchAttributes));
-      } else if (options.getTypedSearchAttributes() != null) {
+      } else if (options.getTypedSearchAttributes() != null
+          && options.getTypedSearchAttributes().size() > 0) {
         attributes.setSearchAttributes(
             SearchAttributesUtil.encodeTyped(options.getTypedSearchAttributes()));
       }

temporal-sdk/src/test/java/io/temporal/workflow/searchattributes/TypedSearchAttributesTest.java

@@ -190,6 +190,32 @@ public void testInvalidSearchAttributeKey() {
     }
   }
 
+  @Test
+  public void testEmptyTypedSearchAttributeKey() {
+    WorkflowOptions options =
+        SDKTestOptions.newWorkflowOptionsWithTimeouts(testWorkflowRule.getTaskQueue()).toBuilder()
+            .setTypedSearchAttributes(io.temporal.common.SearchAttributes.EMPTY)
+            .build();
+    TestSignaledWorkflow stubF =
+        testWorkflowRule.getWorkflowClient().newWorkflowStub(TestSignaledWorkflow.class, options);
+    WorkflowExecution executionF = WorkflowClient.start(stubF::execute);
+
+    GetWorkflowExecutionHistoryResponse historyResp =
+        WorkflowClientHelper.getHistoryPage(
+            testWorkflowRule.getWorkflowServiceStubs(),
+            SDKTestWorkflowRule.NAMESPACE,
+            executionF,
+            ByteString.EMPTY,
+            new NoopScope());
+    HistoryEvent startEvent = historyResp.getHistory().getEvents(0);
+    SearchAttributes searchAttrFromEvent =
+        startEvent.getWorkflowExecutionStartedEventAttributes().getSearchAttributes();
+
+    io.temporal.common.SearchAttributes decoded =
+        SearchAttributesUtil.decodeTyped(searchAttrFromEvent);
+    assertEquals(io.temporal.common.SearchAttributes.EMPTY, decoded);
+  }
+
   @Test
   public void testSearchAttributesPresentInChildWorkflow() {
     NoArgsWorkflow client = testWorkflowRule.newWorkflowStubTimeoutOptions(NoArgsWorkflow.class);