Fix bug in power::expand() with the overall coefficient.

[ginac.git] / ginac / power.cpp

diff --git a/ginac/power.cpp b/ginac/power.cpp
index 62fc3a8ddf070bd5c02a3fe0e2b75ad0006330e6..ba7a66f4bc77cb912947fa06975b2ee801e304d9 100644 (file)
--- a/ginac/power.cpp
+++ b/ginac/power.cpp
@@ -3,7 +3,7 @@
  *  Implementation of GiNaC's symbolic exponentiation (basis^exponent). */
 
 /*
- *  GiNaC Copyright (C) 1999-2018 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2020 Johannes Gutenberg University Mainz, Germany
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -809,9 +809,10 @@ ex power::expand(unsigned options) const
                ex coeff=(possign? _ex1 : _ex_1);
                if (m.overall_coeff.info(info_flags::positive) && m.overall_coeff != _ex1)
                        prodseq.push_back(pow(m.overall_coeff, exponent));
-               else if (m.overall_coeff.info(info_flags::negative) && m.overall_coeff != _ex_1)
+               else if (m.overall_coeff.info(info_flags::negative) && m.overall_coeff != _ex_1) {
                        prodseq.push_back(pow(-m.overall_coeff, exponent));
-               else
+                       coeff = -coeff;
+               } else
                        coeff *= m.overall_coeff;
 
                // If positive/negative factors are found, then extract them.
@@ -1010,16 +1011,16 @@ ex power::expand_add(const add & a, long n, unsigned options)
                                                // optimize away
                                        } else if (exponent[i] == 1) {
                                                // optimized
-                                               monomial.push_back(expair(r, _ex1));
+                                               monomial.emplace_back(expair(r, _ex1));
                                                if (c != *_num1_p)
                                                        factor = factor.mul(c);
                                        } else { // general case exponent[i] > 1
-                                               monomial.push_back(expair(r, exponent[i]));
+                                               monomial.emplace_back(expair(r, exponent[i]));
                                                if (c != *_num1_p)
                                                        factor = factor.mul(c.power(exponent[i]));
                                        }
                                }
-                               result.push_back(expair(mul(std::move(monomial)).expand(options), factor));
+                               result.emplace_back(expair(mul(std::move(monomial)).expand(options), factor));
                        } while (compositions.next());
                } while (partitions.next());
        }
@@ -1063,27 +1064,27 @@ ex power::expand_add_2(const add & a, unsigned options)
                
                if (c.is_equal(_ex1)) {
                        if (is_exactly_a<mul>(r)) {
-                               result.push_back(expair(expand_mul(ex_to<mul>(r), *_num2_p, options, true),
-                                                       _ex1));
+                               result.emplace_back(expair(expand_mul(ex_to<mul>(r), *_num2_p, options, true),
+                                                          _ex1));
                        } else {
-                               result.push_back(expair(dynallocate<power>(r, _ex2),
-                                                       _ex1));
+                               result.emplace_back(expair(dynallocate<power>(r, _ex2),
+                                                          _ex1));
                        }
                } else {
                        if (is_exactly_a<mul>(r)) {
-                               result.push_back(expair(expand_mul(ex_to<mul>(r), *_num2_p, options, true),
-                                                       ex_to<numeric>(c).power_dyn(*_num2_p)));
+                               result.emplace_back(expair(expand_mul(ex_to<mul>(r), *_num2_p, options, true),
+                                                          ex_to<numeric>(c).power_dyn(*_num2_p)));
                        } else {
-                               result.push_back(expair(dynallocate<power>(r, _ex2),
-                                                       ex_to<numeric>(c).power_dyn(*_num2_p)));
+                               result.emplace_back(expair(dynallocate<power>(r, _ex2),
+                                                          ex_to<numeric>(c).power_dyn(*_num2_p)));
                        }
                }
 
                for (auto cit1=cit0+1; cit1!=last; ++cit1) {
                        const ex & r1 = cit1->rest;
                        const ex & c1 = cit1->coeff;
-                       result.push_back(expair(mul(r,r1).expand(options),
-                                               _num2_p->mul(ex_to<numeric>(c)).mul_dyn(ex_to<numeric>(c1))));
+                       result.emplace_back(expair(mul(r,r1).expand(options),
+                                                  _num2_p->mul(ex_to<numeric>(c)).mul_dyn(ex_to<numeric>(c1))));
                }
        }