1 files changed, 55 insertions, 0 deletions
diff --git a/mailnews/addrbook/src/nsAbMDBCard.cpp b/mailnews/addrbook/src/nsAbMDBCard.cpp
new file mode 100644
index 000000000..14af6a875
--- /dev/null
+++ b/mailnews/addrbook/src/nsAbMDBCard.cpp
@@ -0,0 +1,55 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsAbMDBCard.h"
+
+nsAbMDBCard::nsAbMDBCard(void)
+{
+}
+
+nsAbMDBCard::~nsAbMDBCard(void)
+{
+}
+
+NS_IMPL_ISUPPORTS_INHERITED0(nsAbMDBCard, nsAbCardProperty)
+
+NS_IMETHODIMP nsAbMDBCard::Equals(nsIAbCard *card, bool *result)
+{
+  NS_ENSURE_ARG_POINTER(card);
+  NS_ENSURE_ARG_POINTER(result);
+
+  if (this == card) {
+    *result = true;
+    return NS_OK;
+  }
+
+  // If we have the same directory, we will equal the other card merely given
+  // the row IDs. If not, we are never equal. But we are dumb in that we don't
+  // know who our directory is, which may change in the future. For now,
+  // however, the only known users of this method are for locating us in a list
+  // of cards, most commonly mailing lists; a warning on the IDL has also
+  // notified consumers that this method is not generally safe to use. In this
+  // respect, it is safe to assume that the directory portion is satisfied when
+  // making this call.
+  // However, if we make the wrong assumption, one of two things will happen.
+  // If the other directory is a local address book, we could return a spurious
+  // true result. If not, then DbRowID should be unset and we can definitively
+  // return false.
+
+  uint32_t row;
+  nsresult rv = card->GetPropertyAsUint32("DbRowID", &row);
+  if (NS_FAILED(rv))
+  {
+    *result = false;
+    return NS_OK;
+  }
+
+  uint32_t ourRow;
+  rv = GetPropertyAsUint32("DbRowID", &ourRow);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  *result = (row == ourRow);
+  return NS_OK;
+}