QPixmapCache:Remove the old pixmap if you insert one with the same key.

If you insert a new pixmap in the cache with a key that was already in
the cache then we remove the old pixmap and add the new one. This avoid
to fill the memory with garbage even if the cache has a protection to
avoid running out of memory. This was discovered with QraphicsView
and its cache. We don't need to keep old cached pixmaps for an item.

Task-number: KDE
Reviewed-by: Trond

2 files changed, 15 insertions, 0 deletions

diff --git a/src/gui/image/qpixmapcache.cpp b/src/gui/image/qpixmapcache.cpp
index eedb6a3..458d6b9 100644
--- a/src/gui/image/qpixmapcache.cpp
+++ b/src/gui/image/qpixmapcache.cpp
@@ -187,6 +187,11 @@ bool QPMCache::insert(const QString& key, const QPixmap &pixmap, int cost)
         cacheKeys.insert(key, cacheKey);
         return true;
     }
+    qint64 oldCacheKey = cacheKeys.value(key, -1);
+    //If for the same key we add already a pixmap we should delete it
+    if (oldCacheKey != -1)
+        QCache<qint64, QDetachedPixmap>::remove(oldCacheKey);
+
     bool success = QCache<qint64, QDetachedPixmap>::insert(cacheKey, new QDetachedPixmap(pixmap), cost);
     if (success) {
         cacheKeys.insert(key, cacheKey);
diff --git a/tests/auto/qpixmapcache/tst_qpixmapcache.cpp b/tests/auto/qpixmapcache/tst_qpixmapcache.cpp
index c163b52..1f515ff 100644
--- a/tests/auto/qpixmapcache/tst_qpixmapcache.cpp
+++ b/tests/auto/qpixmapcache/tst_qpixmapcache.cpp
@@ -166,6 +166,16 @@ void tst_QPixmapCache::insert()
     QVERIFY(estimatedNum - 1 <= num <= estimatedNum + 1);
     QPixmap p3;
     QPixmapCache::insert("null", p3);
+
+    QPixmap c1(10, 10);
+    c1.fill(Qt::yellow);
+    QPixmapCache::insert("custom", c1);
+    QVERIFY(!c1.isDetached());
+    QPixmap c2(10, 10);
+    c2.fill(Qt::red);
+    QPixmapCache::insert("custom", c2);
+    //We have deleted the old pixmap in the cache for the same key
+    QVERIFY(c1.isDetached());
 }
 
 void tst_QPixmapCache::remove()