X-Git-Url: https://ginac.de/ginac.git//ginac.git?a=blobdiff_plain;f=check%2Fexam_misc.cpp;h=e94ab11b91e62a177e03a401eb159ab974ae9607;hb=be207191d6230add6ddd6aec2ac0b12a0e302f37;hp=9dbfd6bc41d71850566681b337c004d3fea647cc;hpb=67edef78ce992a8f6ad704bfac228b8dec6eacd2;p=ginac.git

diff --git a/check/exam_misc.cpp b/check/exam_misc.cpp
index 9dbfd6bc..e94ab11b 100644
--- a/check/exam_misc.cpp
+++ b/check/exam_misc.cpp
@@ -3,7 +3,7 @@
  */
 
 /*
- *  GiNaC Copyright (C) 1999-2010 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2015 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
@@ -219,6 +219,15 @@ static unsigned exam_subs()
 		++result;
 	}
 
+	// And this used to fail in GiNaC 1.5.8 because it first substituted
+	// exp(x) -> exp(log(x)) -> x, and then substitued again x -> log(x)
+	e1 = exp(x);
+	e2 = e1.subs(x == log(x));
+	if (!e2.is_equal(x)) {
+		clog << "exp(x).subs(x==log(x)) erroneously returned " << e2 << " instead of x" << endl;
+		++result;
+	}
+
 	e1 = sin(1+sin(x));
 	e2 = e1.subs(sin(wild()) == cos(wild()));
 	if (!e2.is_equal(cos(1+cos(x)))) {