Program: 32026
Project: 32026
Buggy source:
/** 
 * Create a direct message room with one participant.<br> The participant can be a user ID or mail address. Once the room is created, on success, the room is set as a "direct message" with the participant.
 * @param aParticipantUserId user ID (or user mail) to be invited in the direct message room
 * @param aCreateRoomCallBack async call back response
 * @return true if the invite was performed, false otherwise
 */
public boolean createRoomDirectMessage(final String aParticipantUserId,final ApiCallback<String> aCreateRoomCallBack){
  boolean retCode=false;
  if (!TextUtils.isEmpty(aParticipantUserId)) {
    retCode=true;
    HashMap<String,Object> params=new HashMap<>();
    params.put("String_Node_Str","String_Node_Str");
    params.put("String_Node_Str",true);
    if (android.util.Patterns.EMAIL_ADDRESS.matcher(aParticipantUserId).matches()) {
      String identityServer=mHsConfig.getIdentityServerUri().toString();
      HashMap<String,String> parameters=new HashMap<>();
      parameters.put("String_Node_Str",identityServer);
      parameters.put("String_Node_Str","String_Node_Str");
      parameters.put("String_Node_Str",aParticipantUserId);
      params.put("String_Node_Str",Arrays.asList(parameters));
    }
 else {
      if (!aParticipantUserId.equals(getMyUserId())) {
        params.put("String_Node_Str",Arrays.asList(aParticipantUserId));
      }
    }
    createRoom(params,new ApiCallback<String>(){
      @Override public void onSuccess(      String roomId){
        final Room room=getDataHandler().getRoom(roomId);
        final String fRoomId=roomId;
        toggleDirectChatRoom(roomId,aParticipantUserId,new ApiCallback<Void>(){
          @Override public void onSuccess(          Void info){
            if (null != aCreateRoomCallBack) {
              aCreateRoomCallBack.onSuccess(fRoomId);
            }
          }
          @Override public void onNetworkError(          Exception e){
            if (null != aCreateRoomCallBack) {
              aCreateRoomCallBack.onNetworkError(e);
            }
          }
          @Override public void onMatrixError(          MatrixError e){
            if (null != aCreateRoomCallBack) {
              aCreateRoomCallBack.onMatrixError(e);
            }
          }
          @Override public void onUnexpectedError(          Exception e){
            if (null != aCreateRoomCallBack) {
              aCreateRoomCallBack.onUnexpectedError(e);
            }
          }
        }
);
      }
      @Override public void onNetworkError(      Exception e){
        if (null != aCreateRoomCallBack) {
          aCreateRoomCallBack.onNetworkError(e);
        }
      }
      @Override public void onMatrixError(      MatrixError e){
        if (null != aCreateRoomCallBack) {
          aCreateRoomCallBack.onMatrixError(e);
        }
      }
      @Override public void onUnexpectedError(      Exception e){
        if (null != aCreateRoomCallBack) {
          aCreateRoomCallBack.onUnexpectedError(e);
        }
      }
    }
);
  }
  return retCode;
}

Fixed version (ground truth):
/** 
 * Create a direct message room with one participant.<br> The participant can be a user ID or mail address. Once the room is created, on success, the room is set as a "direct message" with the participant.
 * @param aParticipantUserId user ID (or user mail) to be invited in the direct message room
 * @param aCreateRoomCallBack async call back response
 * @return true if the invite was performed, false otherwise
 */
public boolean createRoomDirectMessage(final String aParticipantUserId,final ApiCallback<String> aCreateRoomCallBack){
  boolean retCode=false;
  if (!TextUtils.isEmpty(aParticipantUserId)) {
    retCode=true;
    HashMap<String,Object> params=new HashMap<>();
    params.put("String_Node_Str","String_Node_Str");
    params.put("String_Node_Str",true);
    if (android.util.Patterns.EMAIL_ADDRESS.matcher(aParticipantUserId).matches()) {
      HashMap<String,String> parameters=new HashMap<>();
      parameters.put("String_Node_Str",mHsConfig.getIdentityServerUri().getHost());
      parameters.put("String_Node_Str","String_Node_Str");
      parameters.put("String_Node_Str",aParticipantUserId);
      params.put("String_Node_Str",Arrays.asList(parameters));
    }
 else {
      if (!aParticipantUserId.equals(getMyUserId())) {
        params.put("String_Node_Str",Arrays.asList(aParticipantUserId));
      }
    }
    createRoom(params,new ApiCallback<String>(){
      @Override public void onSuccess(      String roomId){
        final String fRoomId=roomId;
        toggleDirectChatRoom(roomId,aParticipantUserId,new ApiCallback<Void>(){
          @Override public void onSuccess(          Void info){
            if (null != aCreateRoomCallBack) {
              aCreateRoomCallBack.onSuccess(fRoomId);
            }
          }
          @Override public void onNetworkError(          Exception e){
            if (null != aCreateRoomCallBack) {
              aCreateRoomCallBack.onNetworkError(e);
            }
          }
          @Override public void onMatrixError(          MatrixError e){
            if (null != aCreateRoomCallBack) {
              aCreateRoomCallBack.onMatrixError(e);
            }
          }
          @Override public void onUnexpectedError(          Exception e){
            if (null != aCreateRoomCallBack) {
              aCreateRoomCallBack.onUnexpectedError(e);
            }
          }
        }
);
      }
      @Override public void onNetworkError(      Exception e){
        if (null != aCreateRoomCallBack) {
          aCreateRoomCallBack.onNetworkError(e);
        }
      }
      @Override public void onMatrixError(      MatrixError e){
        if (null != aCreateRoomCallBack) {
          aCreateRoomCallBack.onMatrixError(e);
        }
      }
      @Override public void onUnexpectedError(      Exception e){
        if (null != aCreateRoomCallBack) {
          aCreateRoomCallBack.onUnexpectedError(e);
        }
      }
    }
);
  }
  return retCode;
}