segmentation fault with dot product of sparse matrices (Trac #1983)

[numpy-gitbot]

Original ticket http://projects.scipy.org/numpy/ticket/1983 on 2011-11-18 by trac user fp4code, assigned to unknown.

The dot product of two sparse matrices crashes python.
The defect has appeared with

commit 867cabefe92b127b765580432b4c05d92342e275
Author: Mark Wiebe <mwiebe@enthought.com>
Date:   Fri Jul 22 10:24:14 2011 -0500

Here an example:

######################################
import sys, numpy, scipy, scipy.sparse
md = numpy.matrix(numpy.zeros((2,2))); md[0,1]=-1; md[1,0]=1
ms = scipy.sparse.lil_matrix(md)
print(sys.version)           # 2.7.2 [GCC 4.5.2]
print(numpy.version.version) # 2.0.0.dev-867cabe to 7297785
print(scipy.version.version) # 0.11.0.dev-badad3f or earlier
print(md*md)                 # OK
print(numpy.dot(md,md))      # OK
print(ms*ms)                 # OK
print(numpy.dot(ms,ms))      # Segmentation fault #
###################################################

[numpy-gitbot]

@nilswagner01 wrote on 2011-11-19

[[-1. 0.]
[ 0. -1.]]
[[-1. 0.]
[ 0. -1.]](0, 0) -1.0
(1, 1) -1.0

Program received signal SIGSEGV, Segmentation fault.
PyArray_MatrixProduct2 (op1=0xce1390, op2=0xce1390, out=0x0)
at numpy/core/src/multiarray/multiarraymodule.c:955
955 Py_INCREF(typec);
(gdb) bt
#0 PyArray_MatrixProduct2 (op1=0xce1390, op2=0xce1390, out=0x0)
at numpy/core/src/multiarray/multiarraymodule.c:955
#1 0x00007ffff5f6dd79 in dotblas_matrixproduct (
__NPY_UNUSED_TAGGEDdummy=,
args=, kwargs=)
at numpy/core/blasdot/_dotblas.c:254
#2 0x00007ffff7b2166c in PyEval_EvalFrameEx ()
from /usr/lib64/libpython2.6.so.1.0
#3 0x00007ffff7b26441 in PyEval_EvalCodeEx ()
from /usr/lib64/libpython2.6.so.1.0
#4 0x00007ffff7b1fa32 in PyEval_EvalCode ()
from /usr/lib64/libpython2.6.so.1.0
#5 0x00007ffff7b3a7a1 in ?? () from /usr/lib64/libpython2.6.so.1.0
#6 0x00007ffff7b3aba4 in PyRun_FileExFlags ()
from /usr/lib64/libpython2.6.so.1.0
#7 0x00007ffff7b3b299 in PyRun_SimpleFileExFlags ()
from /usr/lib64/libpython2.6.so.1.0
#8 0x00007ffff7b42638 in Py_Main () from /usr/lib64/libpython2.6.so.1.0
#9 0x00007ffff6e8eb7d in __libc_start_main () from /lib64/libc.so.6
#10 0x00000000004006e9 in _start ()

[dlax]

I cannot reproduce the segfault with numpy 1.7, scipy 0.13.dev. This was fixed in eb46577.

[seberg]

Thanks for the note. Cannot reproduce current numpy as well (its a bit odd about what happens, but I guess that is just how it is and a different issue).