Fix build with -directwrite

There were several issues caught by GCC:
* deleting object of polymorphic class type which has non-virtual
  destructor might cause undefined behaviour
* comparison between signed and unsigned integer expressions
* 'GetUserDefaultLocaleName' was not declared in this scope
  (depends on WINVER >= 0x0600)

Change-Id: I39f2cc0d5e158f4d85377edd55e9f74a512c7303
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@theqtcompany.com>

1 files changed, 3 insertions, 5 deletions

diff --git a/src/plugins/platforms/windows/qwindowsfontdatabase.cpp b/src/plugins/platforms/windows/qwindowsfontdatabase.cpp
index d1c0249116..b979dc6c4e 100644
--- a/src/plugins/platforms/windows/qwindowsfontdatabase.cpp
+++ b/src/plugins/platforms/windows/qwindowsfontdatabase.cpp
@@ -303,8 +303,7 @@ namespace {
             , m_referenceCount(0)
         {
         }
-
-        ~DirectWriteFontFileStream()
+        virtual ~DirectWriteFontFileStream()
         {
         }
 
@@ -355,7 +354,7 @@ namespace {
         OUT void **fragmentContext)
     {
         *fragmentContext = NULL;
-        if (fragmentSize + fileOffset <= m_fontData.size()) {
+        if (fileOffset + fragmentSize <= quint64(m_fontData.size())) {
             *fragmentStart = m_fontData.data() + fileOffset;
             return S_OK;
         } else {
@@ -384,8 +383,7 @@ namespace {
     {
     public:
         DirectWriteFontFileLoader() : m_referenceCount(0) {}
-
-        ~DirectWriteFontFileLoader()
+        virtual ~DirectWriteFontFileLoader()
         {
         }