Overfllow in libgap interface

[edgarcosta]

Steps To Reproduce

sage: t = tuple(2**15 - i for i in range(2))
sage: for i in range(5):SymmetricGroup(2**16+2**i)(t)._libgap_()
(32767,32768)
(32767,32768)(65537,1)
(32767,32768)(65537,1)(65538,2)(65539,3)
(32767,32768)(65537,1)(65538,2)(65539,3)(65540,4)(65541,5)(65542,6)(65543,7)
(32767,32768)(65537,1)(65538,2)(65539,3)(65540,4)(65541,5)(65542,6)(65543,7)(65544,8)(65545,9)(65546,10)(65547,11)(65548,12)(65549,13)(65550,14)(65551,15)

# things seem to work okay on the Sage side
sage: for i in range(5):SymmetricGroup(2**16+2**i)(t)
(32767,32768)
(32767,32768)
(32767,32768)
(32767,32768)
(32767,32768)
# Or if one starts with libgap.eval
sage: for i in range(5): SymmetricGroup(2**16+2**i)(libgap.eval(str(t)))._libgap_()
(32767,32768)
(32767,32768)
(32767,32768)
(32767,32768)
(32767,32768)

You can find the input for the next one example here: https://gist.github.com/edgarcosta/b79829984882a1130b4c393d2c76acca

which shows a more complicated instance of the bug:

sage: with open("gen.txt") as F: t = list(map(int, F.read().strip('[]').split(",")))
....: g = SymmetricGroup(133056)(t)
....: str(g)[:100]
'(1,57540,25120,1448,104704,13859,56037,108143,58468,62518,100393,105055,34694,44594,112570,94911,226'
sage: g._libgap_()
(1,57540,25120,1448,39168,22052,59100,14610,61565,20424,22325,15039,5029,444,10671,13061,31435,9614,58000,1913,10874,43926,28119,2653,5246,61031,60645,65486,64440,39550,25105,17490,12979,754,12962,24389,27915,2726,52978,9061,23145,4176,58615,10828,57514,48011,65216,11116,55494,5729,39947,38980,44661,15661,57780,27470,20878,37357,3451,60212,49100,39886,5449,34933,1853,2108,7939,13051,33836,1358,53820,44310,38202,57735,15477,37793,4504,24280,2485,45145,34787)(2,57539,25119,1447,39167,22051,59099,14609,61566,20423,22326,15040,5030,443,10672,13062,31436,9613,57999,1914,10873,43925,28120,2654,5245,61032,60646,65485,64439,39549,25106,17489,12980,753,12961,24390,27916,2725,52977,9062,23146,4175,58616,10827,57513,48012,65215,11115,55493,5730,39948,38979,44662,15662,57779,27469,20877,37358,3452,60211,49099,39885,5450,34934,1854,2107,7940,13052,33835,1357,53819,44309,38201,57736,15478,37794,4503,24279,2486,45146,34788)(3,30205,9512,1198,1719,40274,1906,44900,3014,40298,2157,52832,20879,32214,16526,32566,26113,54114,25183,3912,38661)(4,30206,9511,1197,1720,40273,1905,44899,3013,40297,2158,52831,20880,32213,16525,32565,26114,54113,25184,3911,38662)( [...] )

Additional Information

A workaround for the moment is to use the pexpect interface.

Environment

• OS: OSX/Unix
• Sage Version: 10.7.beta1

Checklist

• I have searched the existing issues for a bug report that matches the one I want to file, without success.
• I have read the documentation and troubleshoot guide