Fix PrefixToPreserveState creation by operating against

DeferredLazyReference and not LazyReference.
This was the intended functionality to make sure that the order of
reconstructed values was such that {% set foo = [] %}{% set bar = foo
%}, rather than {% set bar = foo %}{% set foo = [] %} would happen

src/main/java/com/hubspot/jinjava/lib/tag/eager/EagerExecutionResult.java

@@ -3,10 +3,10 @@
 import static com.hubspot.jinjava.util.EagerReconstructionUtils.buildSetTag;
 
 import com.google.common.annotations.Beta;
+import com.hubspot.jinjava.interpret.DeferredLazyReference;
 import com.hubspot.jinjava.interpret.DeferredLazyReferenceSource;
 import com.hubspot.jinjava.interpret.DeferredValueShadow;
 import com.hubspot.jinjava.interpret.JinjavaInterpreter;
-import com.hubspot.jinjava.interpret.LazyReference;
 import com.hubspot.jinjava.objects.serialization.PyishObjectMapper;
 import com.hubspot.jinjava.util.EagerExpressionResolver.EagerExpressionResult;
 import com.hubspot.jinjava.util.EagerReconstructionUtils;
@@ -65,7 +65,7 @@ public PrefixToPreserveState getPrefixToPreserveState() {
       .collect(Collectors.toList());
     filteredEntries
       .stream()
-      .filter(entry -> !(entry.getValue() instanceof LazyReference))
+      .filter(entry -> !(entry.getValue() instanceof DeferredLazyReference))
       .forEach(entry ->
         EagerReconstructionUtils.hydrateBlockOrInlineSetTagRecursively(
           prefixToPreserveState,
@@ -76,11 +76,13 @@ public PrefixToPreserveState getPrefixToPreserveState() {
       );
     filteredEntries
       .stream()
-      .filter(entry -> (entry.getValue() instanceof LazyReference))
+      .filter(entry -> (entry.getValue() instanceof DeferredLazyReference))
       .map(entry ->
         new AbstractMap.SimpleImmutableEntry<>(
           entry.getKey(),
-          PyishObjectMapper.getAsPyishString(entry.getValue())
+          PyishObjectMapper.getAsPyishString(
+            ((DeferredLazyReference) entry.getValue()).getOriginalValue()
+          )
         )
       )
       .sorted((a, b) ->

src/test/java/com/hubspot/jinjava/EagerTest.java

@@ -1158,7 +1158,14 @@ public void itDefersCallTagWithDeferredArgumentSecondPass() {
   @Test
   public void itHandlesDuplicateVariableReferenceModification() {
     expectedTemplateInterpreter.assertExpectedOutputNonIdempotent(
-      "handles-duplicate-variable-reference-modification"
+      "handles-duplicate-variable-reference-modification/test"
+    );
+  }
+
+  @Test
+  public void itHandlesDuplicateVariableReferenceModification2() {
+    expectedTemplateInterpreter.assertExpectedOutputNonIdempotent(
+      "handles-duplicate-variable-reference-modification-2/test"
     );
   }
 

src/test/resources/eager/handles-duplicate-variable-reference-modification-2/test.expected.jinja

@@ -0,0 +1,5 @@
+{% set foo = ['a', 1] %}{% set bar = foo %}{% if deferred %}
+{% do bar.append(2) %}
+{% endif %}
+{% do bar.append(3) %}
+{{ foo ~ 'and' ~ bar }}

src/test/resources/eager/handles-duplicate-variable-reference-modification-2/test.jinja

@@ -0,0 +1,8 @@
+{% set foo = ['a'] -%}
+{%- set bar = foo -%}
+{% do bar.append(1) %}
+{% if deferred %}
+{% do bar.append(2) %}
+{% endif %}
+{% do bar.append(3) %}
+{{ foo ~ 'and' ~ bar }}