pari(string) always returns a value, even when it should not

[jdemeyer]

When executing a PARI command from Sage, a value of 0 is returned when None would be expected. For example, in a gp shell (say, started with sage -gp):

gp> kill(x)   /* No output */

But in Sage:

sage: pari('kill(x)')
0

It should be possible to fix this by checking for gnil (PARI's concept of None) as return value.

Component: interfaces

Author: Jeroen Demeyer

Reviewer: John Cremona

Merged: sage-4.5.3.alpha0

Issue created by migration from https://trac.sagemath.org/ticket/9661

[jdemeyer]

Attachment: 9661.patch.gz

[jdemeyer]

Author: Jeroen Demeyer

[JohnCremona]

comment:5

I'm testing this now on 4.5.2.rc0. Can you say why you included _sig_off ? (I do not claim to understand how Sage/pari signal handling works.) Without this patch there is a return with no _sig_off (unless the call to new_gen does that.)

[JohnCremona]

comment:6

Tests all pass on 4.5.2.rc0 (64-bit ubuntu).

[jdemeyer]

comment:7

Replying to @JohnCremona:

I'm testing this now on 4.5.2.rc0. Can you say why you included _sig_off ? (I do not claim to understand how Sage/pari signal handling works.) Without this patch there is a return with no _sig_off (unless the call to new_gen does that.)

It's exactly as you say, new_gen() calls _sig_off.

[qed777]

Merged: sage-4.5.3.alpha0

[qed777]

Reviewer: John Cremona