fix getCurrentPageLinks segfault on links without target

Makefile

@@ -185,7 +185,8 @@ fetchthirdparty:
 	# CREngine patch: change child nodes' type face
 	# @TODO replace this dirty hack  24.04 2012 (houqp)
 	cd kpvcrlib/crengine/crengine/src && \
-		patch -N -p0 < ../../../lvrend_node_type_face.patch || true
+		patch -N -p0 < ../../../lvrend_node_type_face.patch && \
+		patch -N -p3 < ../../../lvdocview-getCurrentPageLinks.patch || true
 	unzip mupdf-thirdparty.zip -d mupdf
 	# check mupdf's thirdparty libs' version, if not matched, remove the old one
 	# run make fetchthirdparty again to get the latest thirdparty libs.

kpvcrlib/lvdocview-getCurrentPageLinks.patch

@@ -0,0 +1,14 @@
+diff --git a/crengine/src/lvdocview.cpp b/crengine/src/lvdocview.cpp
+index e7a355a..e1178de 100755
+--- a/crengine/src/lvdocview.cpp
++++ b/crengine/src/lvdocview.cpp
+@@ -4539,7 +4539,8 @@ void LVDocView::getCurrentPageLinks(ldomXRangeList & list) {
+ 						if (_list[i]->getStart().getNode() == elem)
+ 							return true; // don't add, duplicate found!
+ 					}
+-                                        _list.add(new ldomXRange(elem->getChildNode(0)));
++					ldomNode * node = elem->getChildNode(0);
++					if ( node ) _list.add(new ldomXRange(node));
+ 				}
+ 				return true;
+ 			}