Added test to use BigDecimal to parse number when requesting it as a long.

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

@@ -39,7 +39,7 @@ public final class LazilyParsedNumber extends Number {
       try {
         return (int) Long.parseLong(value);
       } catch (NumberFormatException nfe) {
-        return new BigInteger(value).intValue(); 
+        return new BigDecimal(value).intValue();
       }
     }
   }
@@ -49,7 +49,7 @@ public final class LazilyParsedNumber extends Number {
     try {
       return Long.parseLong(value);
     } catch (NumberFormatException e) {
-      return new BigInteger(value).longValue(); 
+      return new BigDecimal(value).longValue();
     }
   }
 

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

@@ -152,6 +152,10 @@ public class PrimitiveTest extends TestCase {
     expected = new Long(json);
     actual = gson.fromJson(json, Number.class);
     assertEquals(expected.longValue(), actual.longValue());
+
+    json = "1.0";
+    actual = gson.fromJson(json, Number.class);
+    assertEquals(1L, actual.longValue());
   }
 
   public void testPrimitiveDoubleAutoboxedSerialization() {