Cannot drag actions in Designer on Mac OS X/Cocoa.

QMimeData sub classes reimplementing the formats() might not expose the
temporary "application/x-qt-mime-type-name" mimetype used by DnD. So
make sure that the NSDragPboard PasteBoard will contain this dummy mime
type.

Task-number: QTBUG-7981
Reviewed-by: mortens

2 files changed, 13 insertions, 1 deletions

diff --git a/src/gui/kernel/qclipboard_mac.cpp b/src/gui/kernel/qclipboard_mac.cpp
index f3a971d..49a6cc8 100644
--- a/src/gui/kernel/qclipboard_mac.cpp
+++ b/src/gui/kernel/qclipboard_mac.cpp
@@ -388,6 +388,18 @@ QMacPasteboard::setMimeData(QMimeData *mime_src)
         clear_helper();
         QStringList formats = mime_src->formats();
 
+#ifdef QT_MAC_USE_COCOA
+        // QMimeData sub classes reimplementing the formats() might not expose the
+        // temporary "application/x-qt-mime-type-name" mimetype. So check the existence
+        // of this mime type while doing drag and drop.
+        QString dummyMimeType(QLatin1String("application/x-qt-mime-type-name"));
+        if (!formats.contains(dummyMimeType)) {
+            QByteArray dummyType = mime_src->data(dummyMimeType);
+            if (!dummyType.isEmpty()) {
+                formats.append(dummyMimeType);
+            }
+        }
+#endif
         for(int f = 0; f < formats.size(); ++f) {
             QString mimeType = formats.at(f);
             for (QList<QMacPasteboardMime *>::Iterator it = availableConverters.begin(); it != availableConverters.end(); ++it) {
diff --git a/src/gui/kernel/qcocoaview_mac.mm b/src/gui/kernel/qcocoaview_mac.mm
index 2c35be2..756cf92 100644
--- a/src/gui/kernel/qcocoaview_mac.mm
+++ b/src/gui/kernel/qcocoaview_mac.mm
@@ -1404,7 +1404,7 @@ Qt::DropAction QDragManager::drag(QDrag *o)
 
     // setup the data
     QMacPasteboard dragBoard((CFStringRef) NSDragPboard, QMacPasteboardMime::MIME_DND);
-    dragPrivate()->data->setData(QLatin1String("application/x-qt-mime-type-name"), QByteArray());
+    dragPrivate()->data->setData(QLatin1String("application/x-qt-mime-type-name"), QByteArray("dummy"));
     dragBoard.setMimeData(dragPrivate()->data);
 
     // create the image