Add a flag for when the context has been prepared by the config's exe…

…cution mode already.

This prevents having the meta-context variables get overridden when evaluating an import as it creates a new JinjavaInterpreter based on the current one, which will share the same metaContextVariables set

src/main/java/com/hubspot/jinjava/interpret/Context.java

@@ -115,6 +115,7 @@ public enum Library {
   private boolean throwInterpreterErrors = false;
   private boolean partialMacroEvaluation = false;
   private boolean unwrapRawOverride = false;
+  private boolean preparedByExecutionMode = false;
   private DynamicVariableResolver dynamicVariableResolver = null;
   private final Set<String> metaContextVariables; // These variable names aren't tracked in eager execution
   private Node currentNode;
@@ -217,6 +218,7 @@ public Context(
       this.deferredExecutionMode = parent.deferredExecutionMode;
       this.deferLargeObjects = parent.deferLargeObjects;
       this.throwInterpreterErrors = parent.throwInterpreterErrors;
+      this.preparedByExecutionMode = parent.preparedByExecutionMode;
     }
   }
 
@@ -825,4 +827,12 @@ public void setCurrentNode(final Node currentNode) {
   public boolean isInForLoop() {
     return get(ForTag.LOOP) != null;
   }
+
+  boolean isPreparedByExecutionMode() {
+    return preparedByExecutionMode;
+  }
+
+  void setPreparedByExecutionMode(boolean preparedByExecutionMode) {
+    this.preparedByExecutionMode = preparedByExecutionMode;
+  }
 }

src/main/java/com/hubspot/jinjava/interpret/JinjavaInterpreter.java

@@ -111,8 +111,10 @@ public JinjavaInterpreter(
     this.context = context;
     this.config = renderConfig;
     this.application = application;
-
-    this.config.getExecutionMode().prepareContext(this.context);
+    if (!this.context.isPreparedByExecutionMode()) {
+      this.config.getExecutionMode().prepareContext(this.context);
+      this.context.setPreparedByExecutionMode(true);
+    }
 
     switch (config.getRandomNumberGeneratorStrategy()) {
       case THREAD_LOCAL: