From 3a8a1f83d60ec16e4c61e2b0a327a5af02917a5a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Samuel=20R=C3=B8dal?= <sroedal@trolltech.com>
Date: Thu, 10 Dec 2009 17:22:53 +0100
Subject: Prevented leak of keys in QPixmapCache.

Removing a pixmap from the pixmap cache using the new QPixmapCache::Key
API left the keys dangling in the QCache's internal QHash. The problem
is that the Key is invalidated as soon as the QPixmapCacheEntry is
destroyed, thus removing it from the hash failed. Reordering the
destruction of the object and the removal of the key in QHash fixes the
problem.

Reviewed-by: Alexis
Reviewed-by: Thiago
---
 src/corelib/tools/qcache.h                   |  2 +-
 src/gui/image/qpixmapcache.cpp               |  5 +++++
 tests/auto/qpixmapcache/tst_qpixmapcache.cpp | 19 +++++++++++++++++++
 3 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/src/corelib/tools/qcache.h b/src/corelib/tools/qcache.h
index 46e20b1..ee9523f 100644
--- a/src/corelib/tools/qcache.h
+++ b/src/corelib/tools/qcache.h
@@ -70,8 +70,8 @@ class QCache
         if (l == &n) l = n.p;
         if (f == &n) f = n.n;
         total -= n.c;
-        delete n.t;
         hash.remove(*n.keyPtr);
+        delete n.t;
     }
     inline T *relink(const Key &key) {
         typename QHash<Key, Node>::iterator i = hash.find(key);
diff --git a/src/gui/image/qpixmapcache.cpp b/src/gui/image/qpixmapcache.cpp
index b0b7d72..b7b29d7 100644
--- a/src/gui/image/qpixmapcache.cpp
+++ b/src/gui/image/qpixmapcache.cpp
@@ -424,6 +424,11 @@ QPixmapCache::KeyData* QPMCache::getKeyData(QPixmapCache::Key *key)
 
 Q_GLOBAL_STATIC(QPMCache, pm_cache)
 
+int Q_AUTOTEST_EXPORT q_QPixmapCache_keyHashSize()
+{
+    return pm_cache()->size();
+}
+
 QPixmapCacheEntry::~QPixmapCacheEntry()
 {
     pm_cache()->releaseKey(key);
diff --git a/tests/auto/qpixmapcache/tst_qpixmapcache.cpp b/tests/auto/qpixmapcache/tst_qpixmapcache.cpp
index 9775d36..c89a182 100644
--- a/tests/auto/qpixmapcache/tst_qpixmapcache.cpp
+++ b/tests/auto/qpixmapcache/tst_qpixmapcache.cpp
@@ -70,6 +70,7 @@ private slots:
     void remove();
     void clear();
     void pixmapKey();
+    void noLeak();
 };
 
 static QPixmapCache::KeyData* getPrivate(QPixmapCache::Key &key)
@@ -482,5 +483,23 @@ void tst_QPixmapCache::pixmapKey()
     QVERIFY(!getPrivate(key8));
 }
 
+extern int q_QPixmapCache_keyHashSize();
+
+void tst_QPixmapCache::noLeak()
+{
+    QPixmapCache::Key key;
+
+    int oldSize = q_QPixmapCache_keyHashSize();
+    for (int i = 0; i < 100; ++i) {
+        QPixmap pm(128, 128);
+        pm.fill(Qt::transparent);
+        key = QPixmapCache::insert(pm);
+        QPixmapCache::remove(key);
+    }
+    int newSize = q_QPixmapCache_keyHashSize();
+
+    QCOMPARE(oldSize, newSize);
+}
+
 QTEST_MAIN(tst_QPixmapCache)
 #include "tst_qpixmapcache.moc"
-- 
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