primpart_content: correctly handle monomials.

Impact: fixes (rare) incorrect gcd calculation and (potential) segfault.

Thanks to Aless Lasaruk for a bug report.

diff --git a/ginac/polynomial/collect_vargs.cpp b/ginac/polynomial/collect_vargs.cpp
index 89c3b8bec49321e8adffc70df2db2e8d94f4be9a..259326873bf1da4fd6866a8d2267ec0a13665264 100644 (file)
--- a/ginac/polynomial/collect_vargs.cpp
+++ b/ginac/polynomial/collect_vargs.cpp
@@ -148,8 +148,14 @@ ex_collect_to_ex(const ex_collect_t& ec, const GiNaC::exvector& vars)
                exvector tv;
                tv.reserve(vars.size() + 1);
                for (std::size_t j = 0; j < vars.size(); ++j) {
                exvector tv;
                tv.reserve(vars.size() + 1);
                for (std::size_t j = 0; j < vars.size(); ++j) {

-                       if (ec[i].first[j] != 0)
-                               tv.push_back(power(vars[j], ec[i].first[j]));
+                       const exp_vector_t& exp_vector(ec[i].first);
+
+                       bug_on(exp_vector.size() != vars.size(),
+                               "expected " << vars.size() << " variables, "
+                               "expression has " << exp_vector.size() << " instead");
+
+                       if (exp_vector[j] != 0)
+                               tv.push_back(power(vars[j], exp_vector[j]));

                }
                tv.push_back(ec[i].second);
                ex tmp = (new mul(tv))->setflag(status_flags::dynallocated);
                }
                tv.push_back(ec[i].second);
                ex tmp = (new mul(tv))->setflag(status_flags::dynallocated);

diff --git a/ginac/polynomial/primpart_content.cpp b/ginac/polynomial/primpart_content.cpp
index f703ee709d38a2874ec78384a817b5a3baf7015d..694f29d66dac1e365b6df40eaf5a6d2ed5d07214 100644 (file)
--- a/ginac/polynomial/primpart_content.cpp
+++ b/ginac/polynomial/primpart_content.cpp
@@ -62,7 +62,7 @@ void primpart_content(ex& pp, ex& c, ex e, const exvector& vars,
                // p_1(x_n) p_2(x_0, \ldots, x_{n-1})
                c = ec.rbegin()->second;
                ec.rbegin()->second = ex1;
                // p_1(x_n) p_2(x_0, \ldots, x_{n-1})
                c = ec.rbegin()->second;
                ec.rbegin()->second = ex1;

-               pp = ex_collect_to_ex(ec, vars).expand().smod(numeric(p));
+               pp = ex_collect_to_ex(ec, rest_vars).expand().smod(numeric(p));

                return;
        }
 
                return;
        }