under certain conditions, power::expand_add_2() could produce non-canonical

[ginac.git] / ginac / add.cpp

diff --git a/ginac/add.cpp b/ginac/add.cpp
index 3a7a9126db69f03209f2bb90bafcd8f1574acf3e..1c995aa7f74d9f36f0b98bba4d9173789aa6b1d8 100644 (file)
--- a/ginac/add.cpp
+++ b/ginac/add.cpp
@@ -3,7 +3,7 @@
  *  Implementation of GiNaC's sums of expressions. */
 
 /*
- *  GiNaC Copyright (C) 1999-2001 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2002 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
@@ -121,16 +121,16 @@ void add::print(const print_context & c, unsigned level) const
                while (it != itend) {
                
                        // If the coefficient is -1, it is replaced by a single minus sign
-                       if (it->coeff.compare(_num1) == 0) {
+                       if (it->coeff.is_equal(_ex1)) {
                                it->rest.print(c, precedence());
-                       } else if (it->coeff.compare(_num_1) == 0) {
+                       } else if (it->coeff.is_equal(_ex_1)) {
                                c.s << "-";
                                it->rest.print(c, precedence());
-                       } else if (ex_to<numeric>(it->coeff).numer().compare(_num1) == 0) {
+                       } else if (ex_to<numeric>(it->coeff).numer().is_equal(_num1)) {
                                it->rest.print(c, precedence());
                                c.s << "/";
                                ex_to<numeric>(it->coeff).denom().print(c, precedence());
-                       } else if (ex_to<numeric>(it->coeff).numer().compare(_num_1) == 0) {
+                       } else if (ex_to<numeric>(it->coeff).numer().is_equal(_num_1)) {
                                c.s << "-";
                                it->rest.print(c, precedence());
                                c.s << "/";
@@ -141,14 +141,17 @@ void add::print(const print_context & c, unsigned level) const
                                it->rest.print(c, precedence());
                        }
                
-                       // Separator is "+", except if the following expression would have a leading minus sign
+                       // Separator is "+", except if the following expression would have a leading minus sign or the sign is sitting in parenthesis (as in a ctor)
                        ++it;
-                       if (it != itend && !(it->coeff.compare(_num0) < 0 || (it->coeff.compare(_num1) == 0 && is_exactly_a<numeric>(it->rest) && it->rest.compare(_num0) < 0)))
+                       if (it != itend
+                        && (is_a<print_csrc_cl_N>(c)  // sign inside ctor arguments
+                         || !(it->coeff.info(info_flags::negative) || (it->coeff.is_equal(_num1) && is_exactly_a<numeric>(it->rest) && it->rest.info(info_flags::negative)))))
                                c.s << "+";
                }
        
                if (!overall_coeff.is_zero()) {
-                       if (overall_coeff.info(info_flags::positive))
+                       if (overall_coeff.info(info_flags::positive)
+                        || is_a<print_csrc_cl_N>(c))  // sign inside ctor argument
                                c.s << '+';
                        overall_coeff.print(c, precedence());
                }
@@ -521,7 +524,7 @@ ex add::expand(unsigned options) const
                // the terms have not changed, so it is safe to declare this expanded
                return (options == 0) ? setflag(status_flags::expanded) : *this;
        }
-       
+
        return (new add(vp, overall_coeff))->setflag(status_flags::dynallocated | (options == 0 ? status_flags::expanded : 0));
 }