Acme gags, if pushed too far!!!

Acme gags, if pushed too far!!!

[Fariborz]

In the pcdist version of plan9, acme gags, fairly consistently, if
the second column is pushed too far to the right.  The output is
something like this:

acme: draw: _frcanfit==0: file does not exist
acme 79: suicide: sys: trap: fault write addr=0x0 pc=0x00022ab2
term%

The fastest way to reproduce it, is this:

[1] New a term window.
[2] Start acme.
[3] In the second (rightmost) column, where the directory
    ``/usr/none/'' is displayed, drag the mouse across the `/' while
    holding down the right button, and let go. This stacks a new
    window, below, with the contents of the root directory.
[4] Now move the whole column by placing the mouse on the
    topmost/rightmost solid square; click and hold the right mouse
    button, and move the mouse (column) to the right, passed the right
    edge of the window.

Voila.

Step 3 seems to be important in causing this.  If it is skipped,
nothing happens.

BTW, and after the fact, is this the right place for this kind of
question/bug-report?

-fst

FYI, the system is a Toshiba T2130CT 486DX4 75Mhz, 8 MB, vga
640x480x1, with an AccuPoint (looks like a PS2) pointing device.

Acme gags, if pushed too far!!!

[rob]

This is a silly bug with no easy guaranteed fix.  The code has a check
against the problem but it's too lax.  Change the appearances of the
value 20 in /sys/src/cmd/acme/rows.l to 80 and that should cover
most cases.  A proper fix involves rewriting the underlying frame library,
which may happen someday but not anytime soon.  I have placed the
diffs in the errata web page.  It's not worth posting a new binary; just
avoid making columns so uselessly narrow.

-rob