Fix Hoisted Text Span Symbol Table Bug

Fixes #1042

src/main/java/com/amazon/ion/impl/IonReaderTextUserX.java

@@ -1,18 +1,5 @@
-/*
- * Copyright 2007-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
- *
- * Licensed under the Apache License, Version 2.0 (the "License").
- * You may not use this file except in compliance with the License.
- * A copy of the License is located at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * or in the "license" file accompanying this file. This file is distributed
- * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
- * express or implied. See the License for the specific language governing
- * permissions and limitations under the License.
- */
-
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
 package com.amazon.ion.impl;
 
 import static com.amazon.ion.SystemSymbols.ION_1_0;
@@ -267,6 +254,7 @@ private static final class IonReaderTextSpan
         implements Span, TextSpan, OffsetSpan
     {
         private final UnifiedDataPageX _data_page;
+        private final SymbolTable      _symbols;
         private final IonType          _container_type;
 
         private final long             _start_offset;
@@ -284,6 +272,7 @@ private static final class IonReaderTextSpan
             //       page of buffered input Which is the case for the time
             //       being.  Later, when this is stream aware, this needs to change.
             _data_page = current_stream._buffer.getCurrentPage();
+            _symbols = reader.getSymbolTable();
             _container_type = reader.getContainerType();
 
             _start_offset = reader._value_start_offset - reader._physical_start_offset;
@@ -391,6 +380,7 @@ private void hoistImpl(Span span)
         }
         IonType container = text_span.getContainerType();
         re_init(iis, container, text_span._start_line, text_span._start_column);
+        _symbols = text_span._symbols;
     }
 
 

src/test/java/com/amazon/ion/TextSpanHoistingTest.java

@@ -0,0 +1,50 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+package com.amazon.ion;
+
+import com.amazon.ion.facet.Facets;
+import com.amazon.ion.system.IonReaderBuilder;
+import org.junit.Test;
+import org.junit.jupiter.api.Assertions;
+
+import java.io.IOException;
+
+public class TextSpanHoistingTest
+{
+    @Test
+    public void hoistingTextSpanAlsoHoistsSymbolTable() throws IOException {
+        String textWithSymbolTables =
+                "$ion_1_0 $ion_symbol_table::{ symbols:[\"bar\"] } { foo1: $10 }" +
+                "$ion_1_0 $ion_symbol_table::{ symbols:[\"baz\"] } { foo2: $10 }";
+
+        IonReader reader = IonReaderBuilder.standard().build(textWithSymbolTables);
+        SeekableReader seekableReader = Facets.asFacet(SeekableReader.class, reader);
+
+        Assertions.assertEquals(IonType.STRUCT, reader.next());
+        Span span = seekableReader.currentSpan();
+        reader.stepIn();
+        Assertions.assertEquals(IonType.SYMBOL, reader.next());
+        Assertions.assertEquals("foo1", reader.getFieldName());
+        Assertions.assertEquals("bar", reader.stringValue());
+        reader.stepOut();
+
+        Assertions.assertEquals(IonType.STRUCT, reader.next());
+        reader.stepIn();
+        Assertions.assertEquals(IonType.SYMBOL, reader.next());
+        Assertions.assertEquals("foo2", reader.getFieldName());
+        Assertions.assertEquals("baz", reader.stringValue());
+        reader.stepOut();
+
+        // now re-seek to the first value
+        seekableReader.hoist(span);
+
+        Assertions.assertEquals(IonType.STRUCT, reader.next());
+        reader.stepIn();
+        Assertions.assertEquals(IonType.SYMBOL, reader.next());
+        Assertions.assertEquals("foo1", reader.getFieldName());
+
+        // this assertion fails
+        Assertions.assertEquals("bar", reader.stringValue());
+        reader.stepOut();
+    }
+}