Bug 490867 - Variant fixes: coerce null to empty string, GetIsNull should check correct type, variant base type should be void, r=sdwilsh

Adds a NullVariant derived class of Variant_base.

storage/src/Variant.h

@@ -22,6 +22,7 @@
  *
  * Contributor(s):
  *   Shawn Wilsher <me@shawnwilsher.com> (Original Author)
+ *   Drew Willcoxon <adw@mozilla.com>
  *
  * Alternatively, the contents of this file may be used under the terms of
  * either the GNU General Public License Version 2 or later (the "GPL"), or
@@ -299,6 +300,37 @@ struct variant_blob_traits<PRUint8[]>
   }
 };
 
+/**
+ * NULL type
+ */
+
+class NullVariant : public Variant_base
+{
+public:
+  NS_IMETHOD GetDataType(PRUint16 *_type)
+  {
+    NS_ENSURE_ARG_POINTER(_type);
+    *_type = nsIDataType::VTYPE_EMPTY;
+    return NS_OK;
+  }
+
+  NS_IMETHOD GetAsAUTF8String(nsACString &_str)
+  {
+    // Return a void string.
+    _str.Truncate(0);
+    _str.SetIsVoid(PR_TRUE);
+    return NS_OK;
+  }
+
+  NS_IMETHOD GetAsAString(nsAString &_str)
+  {
+    // Return a void string.
+    _str.Truncate(0);
+    _str.SetIsVoid(PR_TRUE);
+    return NS_OK;
+  }
+};
+
 ////////////////////////////////////////////////////////////////////////////////
 //// Template Implementation
 
@@ -361,7 +393,6 @@ typedef Variant<double> FloatVariant;
 typedef Variant<nsString> TextVariant;
 typedef Variant<nsCString> UTF8TextVariant;
 typedef Variant<PRUint8[]> BlobVariant;
-typedef Variant_base NullVariant;
 
 } // namespace storage
 } // namespace mozilla

storage/src/Variant_inl.h

@@ -65,7 +65,8 @@ inline
 NS_IMETHODIMP
 Variant_base::GetDataType(PRUint16 *_type)
 {
-  *_type = nsIDataType::VTYPE_EMPTY;
+  NS_ENSURE_ARG_POINTER(_type);
+  *_type = nsIDataType::VTYPE_VOID;
   return NS_OK;
 }
 

storage/src/mozStorageRow.cpp

@@ -235,10 +235,11 @@ Row::GetIsNull(PRUint32 aIndex,
                PRBool *_isNull)
 {
   ENSURE_INDEX_VALUE(aIndex, mNumCols);
+  NS_ENSURE_ARG_POINTER(_isNull);
 
   PRUint16 type;
   (void)mData.ObjectAt(aIndex)->GetDataType(&type);
-  *_isNull = type == nsIDataType::VTYPE_VOID;
+  *_isNull = type == nsIDataType::VTYPE_EMPTY;
   return NS_OK;
 }
 

storage/test/unit/test_statement_executeAsync.js

@@ -167,21 +167,25 @@ function test_get_data()
       do_check_neq(null, tuple);
 
       // Check that it's what we expect
+      do_check_false(tuple.getIsNull(0));
       do_check_eq(tuple.getResultByName("string"), tuple.getResultByIndex(0));
       do_check_eq(TEXT, tuple.getResultByName("string"));
       do_check_eq(Ci.mozIStorageValueArray.VALUE_TYPE_TEXT,
                   tuple.getTypeOfIndex(0));
 
+      do_check_false(tuple.getIsNull(1));
       do_check_eq(tuple.getResultByName("number"), tuple.getResultByIndex(1));
       do_check_eq(REAL, tuple.getResultByName("number"));
       do_check_eq(Ci.mozIStorageValueArray.VALUE_TYPE_FLOAT,
                   tuple.getTypeOfIndex(1));
 
+      do_check_true(tuple.getIsNull(2));
       do_check_eq(tuple.getResultByName("nuller"), tuple.getResultByIndex(2));
       do_check_eq(null, tuple.getResultByName("nuller"));
       do_check_eq(Ci.mozIStorageValueArray.VALUE_TYPE_NULL,
                   tuple.getTypeOfIndex(2));
 
+      do_check_false(tuple.getIsNull(3));
       var blobByName = tuple.getResultByName("blober");
       do_check_eq(BLOB.length, blobByName.length);
       var blobByIndex = tuple.getResultByIndex(3);
@@ -199,6 +203,7 @@ function test_get_data()
       do_check_eq(Ci.mozIStorageValueArray.VALUE_TYPE_BLOB,
                   tuple.getTypeOfIndex(3));
 
+      do_check_false(tuple.getIsNull(4));
       do_check_eq(tuple.getResultByName("id"), tuple.getResultByIndex(4));
       do_check_eq(INTEGER, tuple.getResultByName("id"));
       do_check_eq(Ci.mozIStorageValueArray.VALUE_TYPE_INTEGER,