QNetworkDiskCache: Drop the file mmap-ing

Presumably the code at some point would do a
QByteArray::fromRawData-style thing. But now it doesn't do that so
the current code was a bit strange. It would map the content of the file
to memory only to then copy the content into a QByteArray. Then it
reparents the file to the QBuffer, keeping it alive even if its not
needed.

Fixes: QTBUG-92838
Pick-to: 6.1 6.0 5.15
Change-Id: I88f8cd1b64e0fd13d08b5cc4df44661e216da340
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>

1 files changed, 1 insertions, 12 deletions

diff --git a/src/network/access/qnetworkdiskcache.cpp b/src/network/access/qnetworkdiskcache.cpp
index 1ee075cb71..8c71da7f46 100644
--- a/src/network/access/qnetworkdiskcache.cpp
+++ b/src/network/access/qnetworkdiskcache.cpp
@@ -417,18 +417,7 @@ QIODevice *QNetworkDiskCache::data(const QUrl &url)
             buffer->setData(d->lastItem.data.data());
         } else {
             buffer.reset(new QBuffer);
-            // ### verify that QFile uses the fd size and not the file name
-            qint64 size = file->size() - file->pos();
-            const uchar *p = nullptr;
-#if !defined(Q_OS_INTEGRITY)
-            p = file->map(file->pos(), size);
-#endif
-            if (p) {
-                buffer->setData((const char *)p, size);
-                file.take()->setParent(buffer.data());
-            } else {
-                buffer->setData(file->readAll());
-            }
+            buffer->setData(file->readAll());
         }
     }
     buffer->open(QBuffer::ReadOnly);