[GiNaC-devel] Is this a bug?

[Jan private]

Hello Alexei,

while compiling an application with MSVC, I stumbled on this (because
the code crashed)

File: mul.cpp
Function: ex mul::algebraic_subs_mul(const exmap & m, unsigned options)

These two vectors are sized to seq.size():
std::vector<bool> subsed(seq.size(), false);
std::vector<bool> currsubsed(seq.size(), false);

They are then used in:
algebraic_match_mul_with_mul()

This iterates over the nops() of the mul:
for (size_t i=0; i<e.nops(); ++i) {

Can it be that the nops() of the mul is (always) equal to seq.size() +
1? Output of one example:

-----
Code inserted in mul::algebraic_subs_mul():

std::cout << "mul::algebraic_subs_mul: nops: " << this->nops() << ",
seq.size(): " << seq.size() << std::endl;
std::cout << "mul::algebraic_subs_mul: " << tree << *this << dflt <<
std::endl;
------------
Output:

mul::algebraic_subs_mul: nops: 2, seq.size(): 1
mul::algebraic_subs_mul: mul @00769848, hash=0x769820, flags=0x3, nops=2
mm    1 (numeric) @00753360, hash=0x160af41d, flags=0xf
    -----
    overall_coeff
    1/10 (numeric) @00769828, hash=0x36fbefb6, flags=0xf
    =====
-------------

Because the code crashes on the last iteration of the for loop, and if I
size the vectors to seq.size()+1 (or maybe better nops()) it does not
crash any more.

Another possibility is that there is another error earlier on which
results in a mul with seq.size() = 1 and nops() = 2 (for my example).

Regards,
	Jan