ncmul::eval(): don't write beyond the end of the vector.

[ginac.git] / ginac / power.cpp

diff --git a/ginac/power.cpp b/ginac/power.cpp
index 53f7bb8700e9d27ce386ef24b6a5f13f38db4ff0..c6bf7b9770d2fa939eb242fef780f6aa84286dc5 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) 1999-2008 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2010 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
@@ -20,11 +20,6 @@
  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
-#include <vector>
-#include <iostream>
-#include <stdexcept>
-#include <limits>
-
 #include "power.h"
 #include "expairseq.h"
 #include "add.h"
@@ -43,6 +38,11 @@
 #include "relational.h"
 #include "compiler.h"
 
+#include <iostream>
+#include <limits>
+#include <stdexcept>
+#include <vector>
+
 namespace GiNaC {
 
 GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(power, basic,
@@ -240,6 +240,8 @@ bool power::info(unsigned inf) const
                               basis.info(inf);
                case info_flags::expanded:
                        return (flags & status_flags::expanded);
+               case info_flags::positive:
+                       return basis.info(info_flags::positive) && exponent.info(info_flags::real);
                case info_flags::has_indices: {
                        if (flags & status_flags::has_indices)
                                return true;
@@ -537,6 +539,7 @@ ex power::eval(int level) const
                                        if (num_coeff.is_positive()) {
                                                mul *mulp = new mul(mulref);
                                                mulp->overall_coeff = _ex1;
+                                               mulp->setflag(status_flags::dynallocated);
                                                mulp->clearflag(status_flags::evaluated);
                                                mulp->clearflag(status_flags::hash_calculated);
                                                return (new mul(power(*mulp,exponent),
@@ -546,6 +549,7 @@ ex power::eval(int level) const
                                                if (!num_coeff.is_equal(*_num_1_p)) {
                                                        mul *mulp = new mul(mulref);
                                                        mulp->overall_coeff = _ex_1;
+                                                       mulp->setflag(status_flags::dynallocated);
                                                        mulp->clearflag(status_flags::evaluated);
                                                        mulp->clearflag(status_flags::hash_calculated);
                                                        return (new mul(power(*mulp,exponent),
@@ -665,12 +669,23 @@ ex power::eval_ncmul(const exvector & v) const
 
 ex power::conjugate() const
 {
-       ex newbasis = basis.conjugate();
-       ex newexponent = exponent.conjugate();
-       if (are_ex_trivially_equal(basis, newbasis) && are_ex_trivially_equal(exponent, newexponent)) {
-               return *this;
+       // conjugate(pow(x,y))==pow(conjugate(x),conjugate(y)) unless on the
+       // branch cut which runs along the negative real axis.
+       if (basis.info(info_flags::positive)) {
+               ex newexponent = exponent.conjugate();
+               if (are_ex_trivially_equal(exponent, newexponent)) {
+                       return *this;
+               }
+               return (new power(basis, newexponent))->setflag(status_flags::dynallocated);
+       }
+       if (exponent.info(info_flags::integer)) {
+               ex newbasis = basis.conjugate();
+               if (are_ex_trivially_equal(basis, newbasis)) {
+                       return *this;
+               }
+               return (new power(newbasis, exponent))->setflag(status_flags::dynallocated);
        }
-       return (new power(newbasis, newexponent))->setflag(status_flags::dynallocated);
+       return conjugate_function(*this).hold();
 }
 
 ex power::real_part() const