fix a NullPointerException that occurred when creating array filters on non-existent properties

json-path/src/main/java/com/jayway/jsonpath/internal/filter/ArrayEvalFilter.java

@@ -37,6 +37,9 @@ public class ArrayEvalFilter extends PathTokenFilter {
     @Override
     public Object filter(Object obj, JsonProvider jsonProvider) {
         //[?(@.isbn == 10)]
+        if (obj == null){
+          return null;
+        }
         List<Object> src = jsonProvider.toList(obj);
         List<Object> result = jsonProvider.createList();
 

json-path/src/main/java/com/jayway/jsonpath/internal/filter/ArrayIndexFilter.java

@@ -32,6 +32,9 @@ public class ArrayIndexFilter extends PathTokenFilter {
 
     @Override
     public Object filter(Object obj,JsonProvider jsonProvider) {
+        if(obj == null){
+          return null;
+        }
 
         List<Object> src = jsonProvider.toList(obj);
         List<Object> result = jsonProvider.createList();

json-path/src/main/java/com/jayway/jsonpath/internal/filter/ArrayQueryFilter.java

@@ -31,7 +31,9 @@ public class ArrayQueryFilter extends PathTokenFilter {
 
     @Override
     public Object filter(Object obj, JsonProvider jsonProvider, LinkedList<Filter> filters, boolean inArrayContext) {
-
+        if (obj == null){
+          return null;
+        }
         Filter filter = filters.poll();
 
         return filter.doFilter((List)obj);

json-path/src/test/java/com/jayway/jsonpath/JsonPathFilterTest.java

@@ -2,6 +2,10 @@ package com.jayway.jsonpath;
 
 import org.junit.Test;
 
+import com.jayway.jsonpath.internal.filter.FilterFactory;
+import com.jayway.jsonpath.internal.filter.PathTokenFilter;
+import com.jayway.jsonpath.spi.impl.JsonSmartJsonProvider;
+
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -129,4 +133,30 @@ public class JsonPathFilterTest {
         assertEquals(1, res.get(0).intValue());
     }
     
+    @Test
+    public void array_query_filter_on_non_existent_property_returns_null(){
+      final PathTokenFilter hugePage = FilterFactory.createFilter("[?(@.wordCount >= 10000)]");
+      Filter filter = new Filter.FilterAdapter<Object>() {
+        @Override
+        public boolean accept(Object obj) {
+          return hugePage.filter(obj, new JsonSmartJsonProvider()) != null;
+        }
+      };
+      
+      assertEquals(null, JsonPath.read(DOCUMENT, "$.store.book.page[?]", filter));
+    }
+    
+    @Test
+    public void array_eval_filter_on_non_existent_property_returns_null(){
+      final JsonPath hugePage = JsonPath.compile("$.store.book.page[?(@.wordCount >= 10000)]");
+      assertEquals(null, hugePage.read(DOCUMENT));
+    }
+    
+    @Test
+    public void array_index_filter_on_non_existent_property_returns_null(){
+      final JsonPath hugePage = JsonPath.compile("$.store.book.page[12]");
+      assertEquals(null, hugePage.read(DOCUMENT));
+    }
+    
+    
 }