editor mail bug

[Elijah Millgram <Millgram at MIT-OZ>]

In Release 4.5, site configuration 57, on Lisp Machine Apiary-5:

Did C-X M to send mail in the editor.
Minibuffer requested a subject, but I wanted to go back
and edit the text.  Selected the Mail window, got
the cursor in the right place; but this happened:

Abort doesn't seem to get out of this one.

>>Error: The argument ARRAY to ARRAY-ACTIVE-LENGTH, NIL, was of the wrong type.
The function expected an array.
While in the function ARRAY-ACTIVE-LENGTH  (METHOD TV:SHEET COMPUTE-MOTION)  ZWEI:PUT-POINT-AT-PLINE

ARRAY-ACTIVE-LENGTH:  (P.C. = 7)
   Arg 0 (ARRAY): NIL
   Local 1 (TEM): NIL

(METHOD TV:SHEET COMPUTE-MOTION):  (P.C. = 107)
   Arg 0 (SELF): #<ZMACS-WINDOW-PANE Zmacs Window Pane 1 3001252 exposed>
   Arg 1 (SELF-MAPPING-TABLE): TV:SHEET
   Arg 2 (OPERATION): COMPUTE-MOTION
   Arg 3 (STRING): NIL
   Arg 4 (START): 0
   Arg 5 (END): NIL
   Arg 6 (X): 0
   Arg 7 (Y): 0
   Arg 8 (CR-AT-END-P): T
   Arg 9 (STOP-X): 0
   Arg 10 (STOP-Y): 4194303
   Arg 11 (BOTTOM-LIMIT): 4194303
   Arg 12 (RIGHT-LIMIT): NIL
   Arg 13 (ACCOUNT-FOR-CONTINUATION-AFTER): NIL

ZWEI:PUT-POINT-AT-PLINE:  (P.C. = 51)
   Arg 0 (SHEET): #<ZMACS-WINDOW-PANE Zmacs Window Pane 1 3001252 exposed>
   Arg 1 (POINT-LINE): "Lije"
   Arg 2 (POINT-INDEX): 4
   Arg 3 (POINT-PLINE): 24
   Arg 4 (FIRST-BP): ("@comment(-*- MODE:SCRIBE -*-)" 0 NORMAL)
   Arg 5 (LAST-BP): ("     (OTHERWISE (COMPLAIN (AN UNRECOGNIZED-MESSAGE)))))" 55 MOVES)

ZWEI:RECENTER-WINDOW:  (P.C. = 303)
   Arg 0 (WINDOW): #<WINDOW 52456655>
   Arg 1 (RECENTER-TYPE): ABSOLUTE
   Arg 2 (RC1): NIL
   Arg 3 (RC2): NIL

ZWEI:REDISPLAY:  (P.C. = 254)
   Arg 0 (WINDOW): #<WINDOW 52456655>
   --Defaulted args:--
   Arg 1 (RECENTER-TYPE): ABSOLUTE
   Arg 2 (RC1): NIL
   Arg 3 (RC2): NIL
   Arg 4 (FORCE-TO-COMPLETION-P): NIL

ZWEI:REDISPLAY-ALL-WINDOWS:  (P.C. = 36)
   --Defaulted args:--
   Arg 0 (FORCE-TO-COMPLETION-P): NIL
   Arg 1 (SELECT-P): T

(METHOD ZWEI:EDITOR EDIT):  (P.C. = 122)
   Arg 0 (SELF): #<ZMACS-TOP-LEVEL-EDITOR 53421127>
   Arg 1 (SELF-MAPPING-TABLE): #<Map to flavor ZWEI:EDITOR -- 11. IV's, 0. FL's 61300021>
   Arg 2 (OPERATION): EDIT
   --Defaulted args:--
   Arg 3 (TOP-LEVEL-P): T

(METHOD ZWEI:TOP-LEVEL-EDITOR COMBINED EDIT):  (P.C. = 42)
   Arg 0 (SELF): #<ZMACS-TOP-LEVEL-EDITOR 53421127>
   Arg 1 (SELF-MAPPING-TABLE): #<Map to flavor ZWEI:TOP-LEVEL-EDITOR -- 13. IV's, 1. FL's 61300005>
   Rest arg (.DAEMON-CALLER-ARGS.): NIL

Rest of stack:
ZWEI:ZMACS-WINDOW-TOP-LEVEL:  (P.C. = 16)
SI:PROCESS-TOP-LEVEL:  (P.C. = 54)