QNetworkDiskCache: Fix tracking of size during storeItem()

If the file already existed we simply removed the old one without
adjusting the size. So use the removeFile() function which takes care of
that.

Additionally, if the current size was non-null we previously increased
the size (presumably meant to be temporarily but wasn't) and called
expire() which would either:
1. not do anything and return currentCacheSize, if it was not greater
than the max size. This would mean that the size of the file would be
counted twice.
or,
2. discard currentCacheSize, measure the size of the items, and then
remove some items if the total size surpassed the max cache size

Neither of those branches need us to (temporarily) increase
currentCacheSize. It also doesn't attain the (presumed) goal of trying
to keep below the max cache size after having added the new item.

Fixes: QTBUG-95009
Pick-to: 6.2 6.1 5.15
Change-Id: I2b5b13ff473a7aa8169cf2aecfea783c97f2d09a
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>

1 files changed, 1 insertions, 3 deletions

diff --git a/src/network/access/qnetworkdiskcache.cpp b/src/network/access/qnetworkdiskcache.cpp
index 6f02405c0f..7b17540417 100644
--- a/src/network/access/qnetworkdiskcache.cpp
+++ b/src/network/access/qnetworkdiskcache.cpp
@@ -273,14 +273,12 @@ void QNetworkDiskCachePrivate::storeItem(QCacheItem *cacheItem)
     Q_ASSERT(!fileName.isEmpty());
 
     if (QFile::exists(fileName)) {
-        if (!QFile::remove(fileName)) {
+        if (!removeFile(fileName)) {
             qWarning() << "QNetworkDiskCache: couldn't remove the cache file " << fileName;
             return;
         }
     }
 
-    if (currentCacheSize > 0)
-        currentCacheSize += 1024 + cacheItem->size();
     currentCacheSize = q->expire();
     if (!cacheItem->file) {
         QString templateName = tmpCacheFileName();