From: Robert Varga <robert.varga@pantheon.tech>
Date: Sun, 4 Nov 2018 20:24:28 +0000 (+0100)
Subject: Tolerate empty instance identifier in ImmutableNodes.fromInstanceId()
X-Git-Tag: v2.0.6.5~2
X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?a=commitdiff_plain;h=5f061adec828ca39f7b0878141cf2f9eb58af322;p=yangtools.git

Tolerate empty instance identifier in ImmutableNodes.fromInstanceId()

If the user specifies an empty InstanceIdentifier, we fail with an
undocumented NoSuchElementException. Make sure we properly handle
this case by returning a container which matches SchemaContext.NAME.

JIRA: YANGTOOLS-914
Change-Id: I0b503d3bed99d73d88e037d35979c503215f3b52
Signed-off-by: Robert Varga <robert.varga@pantheon.tech>
---

diff --git a/yang/yang-data-impl/src/main/java/org/opendaylight/yangtools/yang/data/impl/schema/ImmutableNodes.java b/yang/yang-data-impl/src/main/java/org/opendaylight/yangtools/yang/data/impl/schema/ImmutableNodes.java
index 3a559b277c..754a87047b 100644
--- a/yang/yang-data-impl/src/main/java/org/opendaylight/yangtools/yang/data/impl/schema/ImmutableNodes.java
+++ b/yang/yang-data-impl/src/main/java/org/opendaylight/yangtools/yang/data/impl/schema/ImmutableNodes.java
@@ -39,6 +39,7 @@ import org.opendaylight.yangtools.yang.model.api.DataSchemaNode;
 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
 
 public final class ImmutableNodes {
+    private static final NodeIdentifier SCHEMACONTEXT_NAME = NodeIdentifier.create(SchemaContext.NAME);
 
     private ImmutableNodes() {
         throw new UnsupportedOperationException("Utilities class should not be instantiated");
@@ -195,13 +196,20 @@ public final class ImmutableNodes {
      */
     public static NormalizedNode<?, ?> fromInstanceId(final SchemaContext ctx, final YangInstanceIdentifier id,
             final Optional<NormalizedNode<?, ?>> deepestElement, final Optional<Entry<QName, ModifyAction>> operation) {
+        final PathArgument topLevelElement;
+        final InstanceIdToNodes<?> instanceIdToNodes;
         final Iterator<PathArgument> it = id.getPathArguments().iterator();
-        final PathArgument topLevelElement = it.next();
-        final DataSchemaNode dataChildByName = ctx.getDataChildByName(topLevelElement.getNodeType());
-        checkNotNull(dataChildByName,
-            "Cannot find %s node in schema context. Instance identifier has to start from root", topLevelElement);
-        final InstanceIdToNodes<?> instanceIdToNodes = InstanceIdToNodes.fromSchemaAndQNameChecked(ctx,
-            topLevelElement.getNodeType());
+        if (it.hasNext()) {
+            topLevelElement = it.next();
+            final DataSchemaNode dataChildByName = ctx.getDataChildByName(topLevelElement.getNodeType());
+            checkNotNull(dataChildByName,
+                "Cannot find %s node in schema context. Instance identifier has to start from root", topLevelElement);
+            instanceIdToNodes = InstanceIdToNodes.fromSchemaAndQNameChecked(ctx, topLevelElement.getNodeType());
+        } else {
+            topLevelElement = SCHEMACONTEXT_NAME;
+            instanceIdToNodes = InstanceIdToNodes.fromDataSchemaNode(ctx);
+        }
+
         return instanceIdToNodes.create(topLevelElement, it, deepestElement, operation);
     }
 }
diff --git a/yang/yang-data-impl/src/test/java/org/opendaylight/yangtools/yang/data/impl/schema/InstanceIdToNodesTest.java b/yang/yang-data-impl/src/test/java/org/opendaylight/yangtools/yang/data/impl/schema/InstanceIdToNodesTest.java
index 778a0945d1..ca75650f94 100644
--- a/yang/yang-data-impl/src/test/java/org/opendaylight/yangtools/yang/data/impl/schema/InstanceIdToNodesTest.java
+++ b/yang/yang-data-impl/src/test/java/org/opendaylight/yangtools/yang/data/impl/schema/InstanceIdToNodesTest.java
@@ -200,4 +200,10 @@ public class InstanceIdToNodesTest {
                 YangInstanceIdentifier.create(rootContainer, leafList, leafListWithValue));
         assertEquals(expectedFilter, filter);
     }
+
+    @Test
+    public void testEmptyInstanceIdentifier() {
+        assertEquals(ImmutableNodes.containerNode(SchemaContext.NAME),
+            ImmutableNodes.fromInstanceId(ctx, YangInstanceIdentifier.EMPTY));
+    }
 }