I think bug deserves a separate entry, rather than just being mentioned in bug 506438 comments 9-12.

1. Produce more output than the scrollback buffer's size.
2. Move the cursor upwards, e.g. "clear" or "echo -ne '\e[5H'"
3. Shrink the window size vertically.

Expected behavior: Drop a line from the bottom.

Actual behavior: Doesn't drop a line from bottom, instead scrolls out one line to the scrollback buffer from the top. In case of "clear" this results in the bash prompt being scrolled out, and the cursor forced back on-screen. The immediate user-facing behavior is that the prompt simply disappears.

In vte-0.40 combined with recent terminfo it's even more prominent, since the "clear" command also clears the scrollback buffer. In this case it's not required that more data was produced than the scrollback's size, it's enough if some contents already made it to the scrollback.

As complicated as it sounds, it boils down to an innocent typo, whereas the intended behavior is already documented correctly.