Merge pull request #1057 from kushagr08/issue-910

fix #910: Updated evaluate.py so that union includes results of both branches, even when identical.

Author: Nicholas Car

rdflib/plugins/sparql/evaluate.py

@@ -127,10 +127,12 @@ def evalJoin(ctx, join):
 
 
 def evalUnion(ctx, union):
+    branch1_branch2 = []
     for x in evalPart(ctx, union.p1):
-        yield x
+        branch1_branch2.append(x)
     for x in evalPart(ctx, union.p2):
-        yield x
+        branch1_branch2.append(x)
+    return branch1_branch2
 
 
 def evalMinus(ctx, minus):

test/test_issue910.py

@@ -0,0 +1,65 @@
+from rdflib import Graph
+import unittest
+
+
+class TestIssue910(unittest.TestCase):
+	def testA(self):
+		g = Graph()
+		q = g.query(
+			"""
+			SELECT * {
+			{ BIND ("a" AS ?a) }
+			UNION
+			{ BIND ("a" AS ?a) }
+			}
+			"""
+		)
+		self.assertEqual(len(q) == 2, True)
+
+	def testB(self):
+		g = Graph()
+		q = g.query(
+			"""
+			SELECT * {
+				{ BIND ("a" AS ?a) }
+				UNION
+				{ VALUES ?a { "a" } }
+				UNION
+				{ SELECT ("a" AS ?a) {} }
+			}
+			"""
+		)
+		self.assertEqual(len(q) == 3, True)
+
+	def testC(self):
+		g = Graph()
+		q = g.query(
+			"""
+			SELECT * {
+				{ BIND ("a" AS ?a) }
+				UNION
+				{ VALUES ?a { "a" } }
+				UNION
+				{ SELECT ("b" AS ?a) {} }
+			}
+			"""
+		)
+		self.assertEqual(len(q) == 3, True)
+
+	def testD(self):
+		g = Graph()
+		q = g.query(
+			"""SELECT * {
+				{ BIND ("a" AS ?a) }
+				UNION
+				{ VALUES ?a { "b" } }
+				UNION
+				{ SELECT ("c" AS ?a) {} }
+			}
+			"""
+		)
+		self.assertEqual(len(q) == 3, True)
+
+
+if __name__ == "__main__":
+	unittest.main()