From: Richard Kreckel <kreckel@ginac.de>
Date: Thu, 17 Dec 2015 21:30:13 +0000 (+0100)
Subject: [bugfix] Make sure add::eval() collects all numeric terms *correctly*.
X-Git-Tag: ginac_1-6-6~3
X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=commitdiff_plain;h=83b067d5b1a232b56039f227a9445cea3dd3225a

[bugfix] Make sure add::eval() collects all numeric terms *correctly*.

This fixes a bug introduced with in 2010 with 89d5356b.
---

diff --git a/check/exam_paranoia.cpp b/check/exam_paranoia.cpp
index 711c64a6..81dda853 100644
--- a/check/exam_paranoia.cpp
+++ b/check/exam_paranoia.cpp
@@ -468,16 +468,26 @@ static unsigned exam_paranoia17()
 }
 
 // Bug in add::eval() could result in numeric terms not being collected into
-// the overall coefficient. Fixed on Sep 22, 2010
+// the overall coefficient. Fixed first on Sep 22, 2010 and again on Dec 17 2015
 static unsigned exam_paranoia18()
 {
+	unsigned result = 0;
+
 	ex sqrt2 = sqrt(ex(2));
-	ex e = 1+2*(sqrt2+1)*(sqrt2-1);
-	if ( e.real_part() != 3 ) {
+	ex e = 1 + 2*(sqrt2+1)*(sqrt2-1);
+	if (e.real_part() != 3) {
 		clog << "real_part(1+2*(sqrt(2)+1)*(sqrt(2)-1)) failed to evaluate to 3\n";
-		return 1;
+		++result;
 	}
-	return 0;
+
+	ex sqrt3 = sqrt(ex(3));
+	ex f = 2 + 2*(sqrt2+1)*(sqrt2-1) - 2*(sqrt3+1)*(sqrt3-1);
+	if (f.real_part() != 0) {
+		clog << "real_part(2+2*(sqrt(2)+1)*(sqrt(2)-1)-3*(sqrt(3)+1)*(sqrt(3)-1)) failed to evaluate to 0\n";
+		++result;
+	}
+
+	return result;
 }
 
 // Bug in mul::conjugate when factors are evaluated at branch cuts, reported as
diff --git a/ginac/add.cpp b/ginac/add.cpp
index ccd49240..1a19d86d 100644
--- a/ginac/add.cpp
+++ b/ginac/add.cpp
@@ -388,11 +388,11 @@ ex add::eval(int level) const
 	if (terms_to_collect) {
 		std::auto_ptr<epvector> s(new epvector);
 		s->reserve(seq_size - terms_to_collect);
-		numeric oc = *_num1_p;
+		numeric oc = *_num0_p;
 		j = seq.begin();
 		while (j != last) {
 			if (unlikely(is_a<numeric>(j->rest)))
-				oc = oc.mul(ex_to<numeric>(j->rest)).mul(ex_to<numeric>(j->coeff));
+				oc = oc.add(ex_to<numeric>(j->rest).mul(ex_to<numeric>(j->coeff)));
 			else
 				s->push_back(*j);
 			++j;