#1881 simplify_sum(sum(k^n,k,1,m)) -> stack overflow

closed
nobody
5
2010-01-31
2010-01-23
No

The following example causes a crash of Maxima:

(%i1) load(simplify_sum)$

(%i2) sum(k^n,k,1,m);
(%o2) 'sum(k^n,k,1,m)

(%i3) simplify_sum(%);

INFO: Control stack guard page unprotected
Control stack guard page temporarily disabled: proceed with caution
Maxima encountered a Lisp error:

Observed with Maxima 5.20post and SBCL 1.0.29.

Dieter Kaiser

Discussion

  • Dieter Kaiser

    Dieter Kaiser - 2010-01-24
    • status: open --> closed
     
  • Dieter Kaiser

    Dieter Kaiser - 2010-01-24

    This is a duplicate of the reported problem Bug ID: 2938078 - Crash on attached input. Again we get an endless loop between the functions maxima-integerp and check-integer-facts.
    Closing this bug report as a duplicate.
    Dieter Kaiser

     
  • Dieter Kaiser

    Dieter Kaiser - 2010-01-28

    Reopen this bug report:

    This bug is not related to the bug ID: 2938078 - Crash on attached input.

    It is not observable with GCL (but present), with CLISP and SBCL Maxima enters an endless loop. Furthermore, I have gone back to old versions of Maxima. I have seen this bug with Maxima 5.16 too.

    The problem is the function $poly in algUtil.mac. The recursion is stopped, when the degree (the last argument to $poly) is equal to -1. But we have a symbolic expression as a degree and $poly loops endlessly.

    (%i7) load(simplify_sum)$

    (%i8) trace(poly);
    (%o8) [poly]

    (%i9) sum(k^n,k,1,n);
    (%o9) 'sum(k^n,k,1,n)

    (%i10) simplify_sum(%);
    1 Enter poly [k,_g,n+2]
    2 Enter poly [k,_g,n+1]
    3 Enter poly [k,_g,n]
    4 Enter poly [k,_g,n-1]
    5 Enter poly [k,_g,n-2]
    6 Enter poly [k,_g,n-3]
    7 Enter poly [k,_g,n-4]
    ...

    Dieter Kaiser

     
  • Dieter Kaiser

    Dieter Kaiser - 2010-01-28
    • status: closed --> open
     
  • Andrej Vodopivec

    Fixed in zeilberger_algorithm.mac rev 1.8.

     
  • Andrej Vodopivec

    • status: open --> closed
     
  • Robert Dodier

    Robert Dodier - 2010-01-31
    • labels: --> Share Libraries
     
  • Robert Dodier

    Robert Dodier - 2010-01-31

    changing resolution to "fixed" per previous comment.

     

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