Plug QMimeData leaks in QXcbClipboard

QXcbClipboard failed to delete the various QMimeData instances
it owns.

For m_xClipboard, where the two QXcbClipboardMime instances are
never the same, fix the leak by using a scoped instead of a
naked pointer.

For m_clientClipboard, where the two QMimeData could be identical
objects, keep the naked pointers, but delete the objects manually
in the QXcbClipboard destructor, paying attention to the case
where they're the same object.

Change-Id: I5ce0e3e8fcec068aeb344ca806cdf2667378e946
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

2 files changed, 8 insertions, 6 deletions

diff --git a/src/plugins/platforms/xcb/qxcbclipboard.cpp b/src/plugins/platforms/xcb/qxcbclipboard.cpp
index 8b75c130fb..d44ebae8f7 100644
--- a/src/plugins/platforms/xcb/qxcbclipboard.cpp
+++ b/src/plugins/platforms/xcb/qxcbclipboard.cpp
@@ -269,8 +269,6 @@ QXcbClipboard::QXcbClipboard(QXcbConnection *c)
 {
     Q_ASSERT(QClipboard::Clipboard == 0);
     Q_ASSERT(QClipboard::Selection == 1);
-    m_xClipboard[QClipboard::Clipboard] = 0;
-    m_xClipboard[QClipboard::Selection] = 0;
     m_clientClipboard[QClipboard::Clipboard] = 0;
     m_clientClipboard[QClipboard::Selection] = 0;
     m_timestamp[QClipboard::Clipboard] = XCB_CURRENT_TIME;
@@ -323,6 +321,10 @@ QXcbClipboard::~QXcbClipboard()
         }
         free(reply);
     }
+
+    if (m_clientClipboard[QClipboard::Clipboard] != m_clientClipboard[QClipboard::Selection])
+        delete m_clientClipboard[QClipboard::Clipboard];
+    delete m_clientClipboard[QClipboard::Selection];
 }
 
 void QXcbClipboard::incrTransactionPeeker(xcb_generic_event_t *ge, bool &accepted)
@@ -372,9 +374,9 @@ QMimeData * QXcbClipboard::mimeData(QClipboard::Mode mode)
         return m_clientClipboard[mode];
     } else {
         if (!m_xClipboard[mode])
-            m_xClipboard[mode] = new QXcbClipboardMime(mode, this);
+            m_xClipboard[mode].reset(new QXcbClipboardMime(mode, this));
 
-        return m_xClipboard[mode];
+        return m_xClipboard[mode].data();
     }
 }
 
@@ -724,7 +726,7 @@ void QXcbClipboard::handleXFixesSelectionRequest(xcb_xfixes_selection_notify_eve
     // here we care only about the xfixes events that come from non Qt processes
     if (event->owner != XCB_NONE && event->owner != owner()) {
         if (!m_xClipboard[mode]) {
-            m_xClipboard[mode] = new QXcbClipboardMime(mode, this);
+            m_xClipboard[mode].reset(new QXcbClipboardMime(mode, this));
         } else {
             m_xClipboard[mode]->reset();
         }
diff --git a/src/plugins/platforms/xcb/qxcbclipboard.h b/src/plugins/platforms/xcb/qxcbclipboard.h
index 10f07047d8..f9a34f4f3d 100644
--- a/src/plugins/platforms/xcb/qxcbclipboard.h
+++ b/src/plugins/platforms/xcb/qxcbclipboard.h
@@ -92,7 +92,7 @@ private:
     QClipboard::Mode modeForAtom(xcb_atom_t atom) const;
 
     // Selection and Clipboard
-    QXcbClipboardMime *m_xClipboard[2];
+    QScopedPointer<QXcbClipboardMime> m_xClipboard[2];
     QMimeData *m_clientClipboard[2];
     xcb_timestamp_t m_timestamp[2];