Handle nested w/o top-level array in Jackson2JsonTokenizer

Issue: SPR-15803

spring-web/src/main/java/org/springframework/http/codec/json/Jackson2Tokenizer.java

@@ -152,8 +152,8 @@ class Jackson2Tokenizer implements Function<DataBuffer, Flux<TokenBuffer>> {
 	}
 
 	private boolean isTopLevelArrayToken(JsonToken token) {
-		return (token == JsonToken.START_ARRAY && this.arrayDepth == 1) ||
+		return this.objectDepth == 0 && ((token == JsonToken.START_ARRAY && this.arrayDepth == 1) ||
-				(token == JsonToken.END_ARRAY && this.arrayDepth == 0);
+				(token == JsonToken.END_ARRAY && this.arrayDepth == 0));
 	}
 
 	public void endOfInput() {

spring-web/src/test/java/org/springframework/http/codec/json/Jackson2TokenizerTests.java

@@ -57,7 +57,7 @@ public class Jackson2TokenizerTests extends AbstractDataBufferAllocatingTestCase
 	}
 
 	@Test
-	public void noTokenizeArrayElements() {
+	public void doNotTokenizeArrayElements() {
 		this.tokenizer = new Jackson2Tokenizer(this.jsonParser, false);
 
 		testTokenize(
@@ -116,7 +116,7 @@ public class Jackson2TokenizerTests extends AbstractDataBufferAllocatingTestCase
 				asList("{\"foo\": \"bar\"}",
 						"{\"foo\": \"baz\"}"));
 
-		// SPR-15803
+		// SPR-15803: nested array
 		testTokenize(
 				singletonList("[" +
 						"{\"id\":\"0\",\"start\":[-999999999,1,1],\"end\":[999999999,12,31]}," +
@@ -129,6 +129,11 @@ public class Jackson2TokenizerTests extends AbstractDataBufferAllocatingTestCase
 						"{\"id\":\"2\",\"start\":[-999999999,1,1],\"end\":[999999999,12,31]}")
 		);
 
+		// SPR-15803: nested array, no top-level array
+		testTokenize(
+				singletonList("{\"speakerIds\":[\"tastapod\"],\"language\":\"ENGLISH\"}"),
+				singletonList("{\"speakerIds\":[\"tastapod\"],\"language\":\"ENGLISH\"}"));
+
 		testTokenize(
 				asList("[{\"foo\": \"foofoo\", \"bar\"",
 						": \"barbar\"},{\"foo\": \"foofoofoo\", \"bar\": \"barbarbar\"}]"),