- resizeline(term, line, term->cols);
- /* FIXME: should we sort the compressed scrollback out here? */
+ /*
+ * Here we resize lines to _at least_ the right length, but we
+ * don't truncate them. Truncation is done as a side effect of
+ * modifying the line.
+ *
+ * The point of this policy is to try to arrange that resizing the
+ * terminal window repeatedly - e.g. successive steps in an X11
+ * opaque window-resize drag, or resizing as a side effect of
+ * retiling by tiling WMs such as xmonad - does not throw away
+ * data gratuitously. Specifically, we want a sequence of resize
+ * operations with no terminal output between them to have the
+ * same effect as a single resize to the ultimate terminal size,
+ * and also (for the case in which xmonad narrows a window that's
+ * scrolling things) we want scrolling up new text at the bottom
+ * of a narrowed window to avoid truncating lines further up when
+ * the window is re-widened.
+ */
+ if (term->cols > line->cols)
+ resizeline(term, line, term->cols);