Long lines in backscroll causes high CPU utilization, hangs gnome-terminal temporarily

Binary package hint: gnome-terminal

Version: Edgy, 2.16.1-0ubuntu1

Steps to reproduce:

1. Open new window
2. Maximize it (197 columns, 64 lines)
3. Set scrollback to 1500 lines (955K)
4. Fill the backscroll with a long line by doing perl -e 'print join("",map{sprintf("%020d",$_)}1..$ARGV[0])' 5000

At this point CPU utilization goes to 100% when performing any operation affecting the window's main client area, such as mousing over the window, opening a menu, switching between adjacent menus, and particularly, selecting a range of text. gnome-terminal is completely unresponsive while the CPU is pegged. Vary the '5000' argument to the perl command in step 4 to adjust for CPU speed.

This is on an AMD Athlon(tm) 64 Processor 3200+. 7 gnome-terminal windows displaying a total of 22 tabs were open before performing the above steps.

  PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
 5087 tod 18 0 182m 94m 12m R 97.2 4.6 35:22.07 gnome-terminal

Note that this may become worse with use -- I was motivated to report this when a buggy script produced a very long single line of output which hung all gnome-terminal windows for ~20 seconds. This was on a window with 7 tabs that had been open and in use for several days.