Fixes #1876 - Null nodes and properties should be ignored when SETting properties

community/cypher/cypher-compiler-2.0/src/main/scala/org/neo4j/cypher/internal/compiler/v2_0/mutation/PropertySetAction.scala

@@ -22,7 +22,6 @@ package org.neo4j.cypher.internal.compiler.v2_0.mutation
 import org.neo4j.cypher.internal.compiler.v2_0._
 import commands.expressions._
 import pipes.QueryState
-import symbols._
 import org.neo4j.graphdb.{Relationship, Node}
 import org.neo4j.helpers.ThisShouldNotHappenError
 
@@ -34,23 +33,23 @@ case class PropertySetAction(prop: Property, e: Expression)
   def exec(context: ExecutionContext, state: QueryState) = {
     implicit val s = state
 
-    val value = makeValueNeoSafe(e(context))
     val qtx = state.query
-    mapExpr(context) match {
-      case (n: Node) =>
-        if ( null == value )
-          propertyKey.getOptId(qtx).foreach(qtx.nodeOps.removeProperty(n.getId, _))
-        else
-          qtx.nodeOps.setProperty(n.getId, propertyKey.getOrCreateId(qtx), value)
-      case (r: Relationship) =>
-        if ( null == value )
-          propertyKey.getOptId(qtx).foreach(qtx.relationshipOps.removeProperty(r.getId, _))
-        else
-          qtx.relationshipOps.setProperty(r.getId, propertyKey.getOrCreateId(qtx), value)
-      case _ =>
-        throw new ThisShouldNotHappenError("Stefan", "This should be a node or a relationship")
+
+    val expr = mapExpr(context)
+    if (expr != null) {
+      val (id, ops) = expr match {
+        case (e: Relationship) => (e.getId, qtx.relationshipOps)
+        case (e: Node) => (e.getId, qtx.nodeOps)
+        case _ => throw new ThisShouldNotHappenError("Stefan", "This should be a node or a relationship")
+      }
+
+      makeValueNeoSafe(e(context)) match {
+        case null => propertyKey.getOptId(qtx).foreach(ops.removeProperty(id, _))
+        case value => ops.setProperty(id, propertyKey.getOrCreateId(qtx), value)
+      }
     }
 
+
     Iterator(context)
   }
 

community/cypher/cypher/CHANGES.txt

@@ -4,6 +4,7 @@ o Fixes bug around MERGE inside a FOREACH inside a FOREACH
 o Makes it possible to write MERGE queries with no already known parts
 o Fixes problem with compiling queries with NOT expressions in them
 o Fixes #1735 - Indexes and AND predicates produce wrong results
+o Fixes #1876 - Null nodes and properties should be ignored when SETting properties
 
 2.0.0-RC1
 ---------

community/cypher/cypher/src/test/scala/org/neo4j/cypher/NullAcceptanceTest.scala

+package org.neo4j.cypher
+
+import org.junit.Test
+
+class NullAcceptanceTest extends ExecutionEngineHelper {
+
+  @Test def null_nodes_should_be_silently_ignored() {
+    // Given empty database
+
+    // When
+    val result = execute("optional match (a:DoesNotExist) set a.prop = 42 return a")
+
+    // Then doesn't throw
+    result.toList
+  }
+
+}
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