Added checks on the validity of the streamId.

jetty-http2/http2-common/src/main/java/org/eclipse/jetty/http2/parser/DataBodyParser.java

@@ -62,6 +62,11 @@ public class DataBodyParser extends BodyParser
             {
                 case PREPARE:
                 {
+                    // SPEC: wrong streamId is treated as connection error.
+                    if (getStreamId() == 0)
+                    {
+                        return notifyConnectionFailure(ErrorCode.PROTOCOL_ERROR, "invalid_data_frame");
+                    }
                     length = getBodyLength();
                     if (isPaddingHigh())
                     {

jetty-http2/http2-common/src/main/java/org/eclipse/jetty/http2/parser/HeadersBodyParser.java

@@ -73,6 +73,11 @@ public class HeadersBodyParser extends BodyParser
             {
                 case PREPARE:
                 {
+                    // SPEC: wrong streamId is treated as connection error.
+                    if (getStreamId() == 0)
+                    {
+                        return notifyConnectionFailure(ErrorCode.PROTOCOL_ERROR, "invalid_headers_frame");
+                    }
                     length = getBodyLength();
                     if (isPaddingHigh())
                     {

jetty-http2/http2-common/src/main/java/org/eclipse/jetty/http2/parser/PriorityBodyParser.java

@@ -51,6 +51,11 @@ public class PriorityBodyParser extends BodyParser
             {
                 case PREPARE:
                 {
+                    // SPEC: wrong streamId is treated as connection error.
+                    if (getStreamId() == 0)
+                    {
+                        return notifyConnectionFailure(ErrorCode.PROTOCOL_ERROR, "invalid_priority_frame");
+                    }
                     int length = getBodyLength();
                     if (length != 5)
                     {

jetty-http2/http2-common/src/main/java/org/eclipse/jetty/http2/parser/ResetBodyParser.java

@@ -49,6 +49,11 @@ public class ResetBodyParser extends BodyParser
             {
                 case PREPARE:
                 {
+                    // SPEC: wrong streamId is treated as connection error.
+                    if (getStreamId() == 0)
+                    {
+                        return notifyConnectionFailure(ErrorCode.PROTOCOL_ERROR, "invalid_rst_stream_frame");
+                    }
                     int length = getBodyLength();
                     if (length != 4)
                     {

jetty-http2/http2-common/src/main/java/org/eclipse/jetty/http2/parser/SettingsBodyParser.java

@@ -64,6 +64,11 @@ public class SettingsBodyParser extends BodyParser
             {
                 case PREPARE:
                 {
+                    // SPEC: wrong streamId is treated as connection error.
+                    if (getStreamId() != 0)
+                    {
+                        return notifyConnectionFailure(ErrorCode.PROTOCOL_ERROR, "invalid_settings_frame");
+                    }
                     length = getBodyLength();
                     settings = new HashMap<>();
                     state = State.SETTING_ID;