From: Alexei Sheplyakov <varg@metalica.kh.ua>
Date: Sat, 8 Aug 2009 10:07:14 +0000 (+0300)
Subject: symmetry::calchash(): be careful to not dereference past-the-end iterator.
X-Git-Tag: release_1-6-0~72
X-Git-Url: https://ginac.de/ginac.git/tutorial/ginac.git?a=commitdiff_plain;h=526825bcee294cb20e37d8db6d5040ba0f8c428f;p=ginac.git

symmetry::calchash(): be careful to not dereference past-the-end iterator.
---

diff --git a/ginac/symmetry.cpp b/ginac/symmetry.cpp
index 9e00a8c8..725506fa 100644
--- a/ginac/symmetry.cpp
+++ b/ginac/symmetry.cpp
@@ -190,7 +190,8 @@ unsigned symmetry::calchash() const
 
 	if (type == none) {
 		v = rotate_left(v);
-		v ^= *(indices.begin());
+		if (!indices.empty())
+			v ^= *(indices.begin());
 	} else {
 		for (exvector::const_iterator i=children.begin(); i!=children.end(); ++i)
 		{