Fixed issue 443 by relying on Streams.parse() to return a JsonNull on empty documents and throw a JsonParseException otherwise.

gson/src/main/java/com/google/gson/JsonParser.java

@@ -15,14 +15,14 @@
  */
 package com.google.gson;
 
+import java.io.IOException;
+import java.io.Reader;
+import java.io.StringReader;
+
 import com.google.gson.internal.Streams;
 import com.google.gson.stream.JsonReader;
 import com.google.gson.stream.JsonToken;
 import com.google.gson.stream.MalformedJsonException;
-import java.io.EOFException;
-import java.io.IOException;
-import java.io.Reader;
-import java.io.StringReader;
 
 /**
  * A parser to parse Json into a parse tree of {@link JsonElement}s
@@ -86,11 +86,6 @@ public final class JsonParser {
       throw new JsonParseException("Failed parsing JSON source: " + json + " to Json", e);
     } catch (OutOfMemoryError e) {
       throw new JsonParseException("Failed parsing JSON source: " + json + " to Json", e);
-    } catch (JsonParseException e) {
-      if (e.getCause() instanceof EOFException) {
-        return JsonNull.INSTANCE;
-      }
-      throw e;
     } finally {
       json.setLenient(lenient);
     }

gson/src/main/java/com/google/gson/internal/Streams.java

@@ -50,6 +50,9 @@ public final class Streams {
       if (isEmpty) {
         return JsonNull.INSTANCE;
       }
+      // We could possibly throw JsonSyntaxException since the stream prematurely ended.
+      // However, it seems safe to throw JsonIOException since the source is an IOException.
+      // Another reason is to maintain backward compatibility.
       throw new JsonIOException(e);
     } catch (MalformedJsonException e) {
       throw new JsonSyntaxException(e);

gson/src/test/java/com/google/gson/JsonParserTest.java

@@ -38,6 +38,13 @@ public class JsonParserTest extends TestCase {
     parser = new JsonParser();
   }
 
+  public void testParseInvalidJson() {
+    try {
+      parser.parse("[[]");
+      fail();
+    } catch (JsonParseException expected) { }
+  }
+
   public void testParseUnquotedStringArrayFails() {
     JsonElement element = parser.parse("[a,b,c]");
     assertEquals("a", element.getAsJsonArray().get(0).getAsString());

gson/src/test/java/com/google/gson/functional/JsonParserTest.java

@@ -50,6 +50,13 @@ public class JsonParserTest extends TestCase {
     gson = new Gson();
   }
 
+  public void testParseInvalidJson() {
+    try {
+      gson.fromJson("[[]", Object[].class);
+      fail();
+    } catch (JsonSyntaxException expected) { }
+  }
+
   public void testDeserializingCustomTree() {
     JsonObject obj = new JsonObject();
     obj.addProperty("stringValue", "foo");