GtkScrolledWindow containing GtkTextView containing a TextBuffer can't keep at bottom of Buffer

["Thomas A. Moulton" <tom moulton us>]

I see a lot of questions about this and I have not found an answer that 
works for me.

I create the chat window like this:

CHAT *ChatNew(char *player) {
    CHAT *chatlog;
    GtkBox *chat;
    GtkTextBuffer *buf;
    GtkTextView *text;
    GtkEntry *entry;
    GtkScrolledWindow *scroll;
    GtkTextIter endit;

    text = (GtkTextView *)gtk_text_view_new();
    gtk_text_view_set_editable(text, FALSE);
    gtk_text_view_set_wrap_mode(text, GTK_WRAP_WORD_CHAR);
    gtk_text_view_set_cursor_visible(text, FALSE);
    buf = gtk_text_buffer_new(NULL);
    printf("New TextBuffer %x\r\n", (int)buf);
    gtk_text_view_set_buffer(text, buf);

    scroll = (GtkScrolledWindow *)gtk_scrolled_window_new(NULL, NULL);
    gtk_scrolled_window_set_policy(scroll, GTK_POLICY_NEVER, 
GTK_POLICY_ALWAYS);
    gtk_scrolled_window_add_with_viewport(scroll, GTK_WIDGET(text));

    entry =  (GtkEntry *)gtk_entry_new();
    gtk_widget_set_size_request(GTK_WIDGET(entry), -1, 30);

    chat = GTK_BOX(gtk_box_new(GTK_ORIENTATION_VERTICAL, 0));
    gtk_box_pack_start(chat, GTK_WIDGET(scroll), TRUE, TRUE, 0);
    gtk_box_pack_end(chat, (GtkWidget *)entry, FALSE, TRUE, 0);

    chatlog = g_malloc0(sizeof(CHAT));
    if (chatlog == NULL) return NULL;
    strcpy(chatlog->player, player);
    chatlog->scroll = scroll;
    chatlog->box = chat;
    chatlog->text = text;
    chatlog->entry = entry;
    g_signal_connect(G_OBJECT(entry), "activate", 
G_CALLBACK(Enter_Chat), (gpointer)chatlog);
    //buf = gtk_text_view_get_buffer(chatlog->text);

    gtk_text_buffer_get_end_iter(buf, &endit);
    gtk_text_buffer_create_mark(buf, "eob", &endit, FALSE);
    g_signal_connect(G_OBJECT(buf), "changed", 
G_CALLBACK(Chat_scroll_to_end), (gpointer)text);
    //g_signal_connect(G_OBJECT(buf), "key_press_event", 
G_CALLBACK(Chat_keys), (gpointer)chatlog);
    return chatlog;
}

The caller adds it to a GtkNotebook

        if (item == NULL) {
            chatlog = ChatNew(name);
            label = (GtkLabel *)gtk_label_new(name);
            g_queue_insert_sorted(gfibs.chats, chatlog, 
chatNB_sort_chat, 0);
            n = gtk_notebook_insert_page(nb, (GtkWidget *)chatlog->box, 
(GtkWidget *)label, 2);
            buf = gtk_text_view_get_buffer(chatlog->text);
            textv = chatlog->text;
            gtk_widget_show((GtkWidget *)chatlog->scroll);
            gtk_widget_show((GtkWidget *)chatlog->box);
            gtk_widget_show((GtkWidget *)chatlog->text);
            gtk_widget_show((GtkWidget *)chatlog->entry);
            gtk_widget_show((GtkWidget *)label);
            printf("chat inserted at %d\r\n", n);
        } else {
            chatlog = (CHAT *)item->data;
            buf = NULL;
            if (chatlog != NULL && chatlog->text != NULL) {
                buf = gtk_text_view_get_buffer(chatlog->text);
                textv = chatlog->text;
                n = gtk_notebook_page_num(nb, GTK_WIDGET(chatlog->box));
            }
        }


    if (buf != NULL) {
        GtkTextIter endit;
        gtk_text_buffer_get_end_iter(buf, &endit);
        gtk_text_buffer_insert_with_tags(buf, &endit, line, -1, NULL, 
NULL);
        return TRUE;
   }

and then to make sure it is visible

void Chat_scroll_to_end(GtkTextBuffer *buf, GtkTextView *text) {
    GtkTextMark *mark;
    printf("Chat_scroll_to_end arg %x text %x parent %x\r\n", (int)buf, 
(int)text,
            (int)gtk_widget_get_parent(GTK_WIDGET(buf)));fflush(stdout);
    mark = gtk_text_buffer_get_mark(buf, "eob");
    gtk_text_view_scroll_mark_onscreen(text, mark);
}

The printf above at times tells me the objects are not valid, but the 
addresses have not changed.
Also the TextBuffer has a parent of 0! I even allocated and set the 
buffer manually.

If there it no anything obvious wrong here I will strip it down to a 
simpler test case

Tom