sdl@linus.UUCP (Steven D. Litvintchouk) (06/09/89)
[This bug report is really intended for Bob Leivian, the author of
Less. I have taken the liberty of posting it here because I have had
trouble emailing him stuff in the past.]
I have just experimented some more with duplicating the (amiga) bug
involving Less v1.3 and GOMF 3.0. Here's what I found:
First, I started up GOMF 3.0, with low memory vector checking *enabled*.
To experiment with running Less v1.3, I selected a Fish disk (#150) at
random. (Nothing special about the particular disk.)
I double-clicked on the file icon for the disk file "contents" (this
file has Less v1.3 for its default tool). This started up Less v1.3
(from Workbench), displaying the first screenful of text from the
"contents" file.
Immediately, GOMF 3.0 displayed the following requester:
Alert Error Number $81000001
User Program Counter unknown
Trap or Exception table was trashed.
68000 vector at location $00000078
was corrupted with value $0026EDA0
(According to the GOMF 3.0 manual, the alert code $81000001 means
"68000 exception vector checksum.")
Then I quit out of Less. I next selected the "GOMF" option in the
GOMF requester. GOMF then displayed the message: "The damage to the
low memory vector table has been repaired. GOMF could not determine
which task caused the error."
I then repeated the same sequence of steps. I invoked Less the same
way, and again GOMF displayed the same error requester (same 68000
vector location), except that this time it was corrupted with value
$0026F120.
I also tried running Less v1.3 from the CLI. I got the same GOMF
error requester, except that this time the location $00000078 was
corrupted with value $0024FAD0.
Next, I tried running GOMF 3.0, with low memory vector checking
*disabled*.
I then started up Less v1.3 on a text file (displaying one
screenful of text), and immediately quit out of Less. If I then
selected a drawer icon, I got an immediate Guru Meditation crash:
#00000004.0024A2E0
I was able to repeat this bug also.
Finally, I disabled GOMF 3.0 altogether--not running it at all. When
I tried the above sequence--starting up Less v1.3, quitting out of it
immediately, and selecting a drawer icon, everything worked fine. I
have been unable to cause a crash or other bug by running Less v1.3
without running GOMF 3.0 first.
So it appears that there is some strange interaction bug between Less
v1.3 and GOMF 3.0.
To summarize: If you intend to run Less v1.3, then either run GOMF
3.0 with low memory vector checking *enabled*, or don't run GOMF 3.0
at all!
Steven Litvintchouk
MITRE Corporation
Burlington Road
Bedford, MA 01730
Fone: (617)271-7753
ARPA: sdl@mitre-bedford.arpa
UUCP: ...{att,decvax,genrad,ll-xn,philabs,utzoo}!linus!sdl
"Those who will be able to conquer software will be able to
conquer the world." -- Tadahiro Sekimoto, president, NEC Corp.