Fix find_child_by_attribute assertion for attributes with null name/value.

git-svn-id: http://pugixml.googlecode.com/svn/trunk@920 99668b35-9821-0410-8761-19e4c4f06640

2 files changed, 27 insertions, 2 deletions

diff --git a/src/pugixml.cpp b/src/pugixml.cpp
index 4035ab1..03a4b9f 100644
--- a/src/pugixml.cpp
+++ b/src/pugixml.cpp
@@ -4507,7 +4507,7 @@ namespace pugi
 			if (i->name && impl::strequal(name_, i->name))
 			{
 				for (xml_attribute_struct* a = i->first_attribute; a; a = a->next_attribute)
-					if (impl::strequal(attr_name, a->name) && impl::strequal(attr_value, a->value))
+					if (a->name && impl::strequal(attr_name, a->name) && impl::strequal(attr_value, a->value ? a->value : PUGIXML_TEXT("")))
 						return xml_node(i);
 			}
 
@@ -4520,7 +4520,7 @@ namespace pugi
 		
 		for (xml_node_struct* i = _root->first_child; i; i = i->next_sibling)
 			for (xml_attribute_struct* a = i->first_attribute; a; a = a->next_attribute)
-				if (impl::strequal(attr_name, a->name) && impl::strequal(attr_value, a->value))
+				if (a->name && impl::strequal(attr_name, a->name) && impl::strequal(attr_value, a->value ? a->value : PUGIXML_TEXT("")))
 					return xml_node(i);
 
 		return xml_node();
diff --git a/tests/test_dom_traverse.cpp b/tests/test_dom_traverse.cpp
index 738b53d..1af8572 100644
--- a/tests/test_dom_traverse.cpp
+++ b/tests/test_dom_traverse.cpp
@@ -537,6 +537,31 @@ TEST_XML(dom_node_find_child_by_attribute, "<node><stub attr='value3' /><child1
 	CHECK(node.find_child_by_attribute(STR("attr3"), STR("value")) == xml_node());
 }
 
+TEST(dom_node_find_child_by_attribute_null)
+{
+	xml_document doc;
+	xml_node node0 = doc.append_child();
+	xml_node node1 = doc.append_child(STR("a"));
+	xml_node node2 = doc.append_child(STR("a"));
+	xml_node node3 = doc.append_child(STR("a"));
+
+	// this adds an attribute with null name and/or value in the internal representation
+	node1.append_attribute(STR(""));
+	node2.append_attribute(STR("id"));
+	node3.append_attribute(STR("id")) = STR("1");
+
+	// make sure find_child_by_attribute works if name/value is null
+	CHECK(doc.find_child_by_attribute(STR("unknown"), STR("wrong")) == xml_node());
+	CHECK(doc.find_child_by_attribute(STR("id"), STR("wrong")) == xml_node());
+	CHECK(doc.find_child_by_attribute(STR("id"), STR("")) == node2);
+	CHECK(doc.find_child_by_attribute(STR("id"), STR("1")) == node3);
+
+	CHECK(doc.find_child_by_attribute(STR("a"), STR("unknown"), STR("wrong")) == xml_node());
+	CHECK(doc.find_child_by_attribute(STR("a"), STR("id"), STR("wrong")) == xml_node());
+	CHECK(doc.find_child_by_attribute(STR("a"), STR("id"), STR("")) == node2);
+	CHECK(doc.find_child_by_attribute(STR("a"), STR("id"), STR("1")) == node3);
+}
+
 struct find_predicate_const
 {
 	bool result;