Surviving out of memory in Qt Quick app

The QtQuickPlayground app contains a version of samegame which allow
the user to edit the code. By setting the ball size to 8, the app can
run out of memory. This leaves it in a pretty bad state. But apps
on Symbian shouldn't crash due to OOM and should allow some operation.

This change fixes the immediate OOM crashes in declarative, gui and
corelib. It shows warning dialogs which explain what has gone wrong and
leaves the app in a state that can be exited cleanly
from the Symbian task list.

Task-number: QT-5319
Reviewed-by: Shane Kearns
Reviewed-by: Gareth Stockwell
Reviewed-by: Martin Jones

1 files changed, 5 insertions, 8 deletions

diff --git a/src/corelib/global/qglobal.cpp b/src/corelib/global/qglobal.cpp
index 84d68e5..3675fc7 100644
--- a/src/corelib/global/qglobal.cpp
+++ b/src/corelib/global/qglobal.cpp
@@ -2207,16 +2207,13 @@ void qt_message_output(QtMsgType msgType, const char *buf)
         OutputDebugString(reinterpret_cast<const wchar_t *> (fstr.utf16()));
 #elif defined(Q_OS_SYMBIAN)
         // RDebug::Print has a cap of 256 characters so break it up
-        _LIT(format, "[Qt Message] %S");
-        const int maxBlockSize = 256 - ((const TDesC &)format).Length();
+        char format[] = "[Qt Message] %S";
+        const int maxBlockSize = 256 - sizeof(format);
         const TPtrC8 ptr(reinterpret_cast<const TUint8*>(buf));
-        HBufC* hbuffer = HBufC::New(qMin(maxBlockSize, ptr.Length()));
-        Q_CHECK_PTR(hbuffer);
-        for (int i = 0; i < ptr.Length(); i += hbuffer->Length()) {
-            hbuffer->Des().Copy(ptr.Mid(i, qMin(maxBlockSize, ptr.Length()-i)));
-            RDebug::Print(format, hbuffer);
+        for (int i = 0; i < ptr.Length(); i += maxBlockSize) {
+            TPtrC8 part(ptr.Mid(i, qMin(maxBlockSize, ptr.Length()-i)));
+            RDebug::Printf(format, &part);
         }
-        delete hbuffer;
 #else
         fprintf(stderr, "%s\n", buf);
         fflush(stderr);