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 e5d36ee362d7879cf2afb12bc862d2d923acb1d0..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) 1999-2019 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.