c++ - Gstreamer appsrc: odd behaviour of need-data callback -

i'm implementing gstreamer media player own source of data using appsrc. works fine except 1 thing:
when stream reaches it's end, callback emits "end-of-stream" signal. signals sending fucntion
g_signal_emit_by_name(appsrc, "end-of-stream", &ret)
returns gstflowreturn value gst_flow_ok. calls need-data callback again, returns "end-of-stream" signal again. , time gstflowreturn value (-3) gst_flow unexpected. assume not expect "end-of-stream" signal when recieved one, why requests more data than? maybe because didn't set size value iof steam?

gstreamer version 0.10.
callback function code (appsrc type seekable btw):

static void cb_need_data (gstelement *appsrc, guint size, gpointer user_data) {     gstbuffer *buffer;     gstflowreturn ret;     appsrcdata* data = static_cast<appsrcdata*>(user_data);     buffer = gst_buffer_new_and_alloc(size);      int read = fread(gst_buffer_data(buffer), 1, size, data->file);     gst_buffer_size(buffer) = read;      g_signal_emit_by_name (appsrc, "push-buffer", buffer, &ret);      if (ret != gst_flow_ok) {         /* wrong, stop pushing */        g_printerr("gst_flow != ok, return value %d\n", ret);        g_main_loop_quit (data->loop);     }      if(feof(data->file) || read == 0)     {         g_signal_emit_by_name(appsrc, "end-of-stream", &ret);         if (ret != gst_flow_ok) {            g_printerr("eof reached, gst_flow != ok, return value %d\naborting...", ret);            g_main_loop_quit (data->loop);         }     } } 

you should provide corrections code(if not there already) should alleviate issue , overall application:

1. never try , send buffer without first checking if has data. so, check buffer data , length make sure data not null , length >0
2. you can flag stream ended in user_data. when send eos, set item in userdata indicate has been sent , if appsrc requests more data, check if has been sent , not send else buffer.
3. listen eos on pipeline bus can destroy stream , close loop when eos message handled can sure mediasink has received eos , can safely dispose of pipeline , loop without losing data.