Number: 1349

Date:  5-Jun-84 14':50':18

Submitter: Sannella.PA

Source: Martin Yonke <Yonke@USC-ECL.ARPA>

Subject: REVERT to \INTERPRETER causes infinite loop and leave break in

Assigned To: 

Attn: burton

Status: Fixed

In/By: 

Problem Type: Bug

Impact: Minor

Difficulty: Moderate

Frequency: Intermittent

Priority: Perhaps

System: Programming Environment

Subsystem: Break Package

Machine: 

Disk: 

Lisp Version: 

Source Files: 

Microcode Version: 

Memory Size: 

File Server: 

Server Software Version: 

Disposition: '
["burton.pa" "29-Aug-84 16':10':29" Status':(Open->Fixed) Description':]

Description: '
Return-Path': <YONKE@USC-ECL.ARPA>'
Received': from USC-ECL.ARPA by Xerox.ARPA ; 29 MAY 84 15':31':44 PDT'
Date': Mon, 28 May 84 16':18':19 PDT'
From': Martin Yonke <Yonke@USC-ECL.ARPA>'
Subject': ''revert'' from a break can be deadly to 1108s'
To': LispSupport.pa'
'
If you get a UDF running noncompiled code and you ''revert'' either by'
menu or typein before you "assign" a place to go (and LASTPOS is a stack'
pointer to \INTERPRETER) the 1108 stops -- MP=0 but mouse is dead.'
'
Martin'
'
P.S. the reason I sent this to you instead of 1100Support is that the'
person who reported it said it used to work -- i.e. he said he would'
define the function that caused the UDF and then ''revert'' and it would'
work but it doesn''t in Fugue.6 (9-Apr release).  You might just want to'
forward it to them if this is not true.  /mdy'
-------'
'
I tried this on a dorado.  The system first insisted that I mouse confirm reverting to a dummyframep then got a stack overflow.  I don''t know anything about it working in earlier releases except that I don''t believe it was even possible to revert to a dummyframep until recently.  Maybe Marty''s user was reverting to something else (like the function being interpreted).  I changed the status to "intermittent" though it might well be "always" and made it a microcode problem for Steve.  -- rrb'
'
Later I discovered that the definition of \INTERPRETER1 had been left broken by the above revert.  I patched it via "_" to move the definition from the break function (\INTERPRETER1B0010 in my case) to INTERPRETER1. I changed description to reflect this.  rrb'
-------------'
Date': 29 Aug 84 16':09 PDT'
From': burton.pa'
Subject': ar 1349': revert to \INTERPRETER loops'
To': Yonke@usc-ecl.arpa'
cc': masinter, burton.pa'
'
Last weekend, Larry changed the way revert works to fix this bug.  Should be out in the Harmony release.'
'
Richard'
'


Workaround: 

Test Case: 

Edit-By: burton.pa

Edit-Date: 29-Aug-84 16':10':30