http trouble again, segfaults when no internet

[kandalf]

It seems like you're deleting some wrong pointer. But I'm just guessing. I haven't tried your code without connection yet, and haven't looked the code deeply neither but, maybe you should take a closer look at Image::httpDone(bool) slot where you're deleting objects.
Anyways, I agrre with Wysota, you should run your app with gdb and see where it crashes.

Cheers.

[guilugi]

Hello,

I tested on a Linux Debian, and here is the backtrace from gdb:

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread -1220528448 (LWP 8604)]
0xb79b009d in QMetaObject::activate () from /usr/lib/libQtCore_debug.so.4
(gdb) where
#0  0xb79b009d in QMetaObject::activate () from /usr/lib/libQtCore_debug.so.4
#1  0xb79b0a2c in QMetaObject::activate () from /usr/lib/libQtCore_debug.so.4
#2  0xb7a4e171 in QHttp::stateChanged () from /usr/lib/libQtNetwork_debug.so.4
#3  0xb7a4e22a in QHttpPrivate::setState () from /usr/lib/libQtNetwork_debug.so.4
#4  0xb7a4edfd in QHttpPrivate::closeConn () from /usr/lib/libQtNetwork_debug.so.4
#5  0xb7a56f68 in QHttpPrivate::slotError () from /usr/lib/libQtNetwork_debug.so.4
#6  0xb7a592a9 in QHttp::qt_metacall () from /usr/lib/libQtNetwork_debug.so.4
#7  0xb79b05b1 in QMetaObject::activate () from /usr/lib/libQtCore_debug.so.4
#8  0xb79b0a2c in QMetaObject::activate () from /usr/lib/libQtCore_debug.so.4
#9  0xb7a68e94 in QAbstractSocket::error () from /usr/lib/libQtNetwork_debug.so.4
#10 0xb7a6b244 in QAbstractSocketPrivate::startConnecting () from /usr/lib/libQtNetwork_debug.so.4
#11 0xb7a6c859 in QAbstractSocket::qt_metacall () from /usr/lib/libQtNetwork_debug.so.4
#12 0xb7a770f2 in QTcpSocket::qt_metacall () from /usr/lib/libQtNetwork_debug.so.4
#13 0xb79af815 in QObject::event () from /usr/lib/libQtCore_debug.so.4
#14 0xb7b4d8b4 in QApplicationPrivate::notify_helper () from /usr/lib/libQtGui_debug.so.4
#15 0xb7b4e8c9 in QApplication::notify () from /usr/lib/libQtGui_debug.so.4
#16 0xb79a444d in QCoreApplication::sendPostedEvents () from /usr/lib/libQtCore_debug.so.4
#17 0xb7bb5711 in QEventDispatcherX11::processEvents () from /usr/lib/libQtGui_debug.so.4
#18 0xb79a1a24 in QEventLoop::processEvents () from /usr/lib/libQtCore_debug.so.4
#19 0xb79a1c76 in QEventLoop::exec () from /usr/lib/libQtCore_debug.so.4
#20 0xb79a4611 in QCoreApplication::exec () from /usr/lib/libQtCore_debug.so.4
#21 0xb7b4d5d7 in QApplication::exec () from /usr/lib/libQtGui_debug.so.4
#22 0x0804d0a3 in main (argc=1, argv=0xbfee1394) at imgtestdialog.cpp:216

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread -1220528448 (LWP 8604)]
0xb79b009d in QMetaObject::activate () from /usr/lib/libQtCore_debug.so.4
(gdb) where
#0  0xb79b009d in QMetaObject::activate () from /usr/lib/libQtCore_debug.so.4
#1  0xb79b0a2c in QMetaObject::activate () from /usr/lib/libQtCore_debug.so.4
#2  0xb7a4e171 in QHttp::stateChanged () from /usr/lib/libQtNetwork_debug.so.4
#3  0xb7a4e22a in QHttpPrivate::setState () from /usr/lib/libQtNetwork_debug.so.4
#4  0xb7a4edfd in QHttpPrivate::closeConn () from /usr/lib/libQtNetwork_debug.so.4
#5  0xb7a56f68 in QHttpPrivate::slotError () from /usr/lib/libQtNetwork_debug.so.4
#6  0xb7a592a9 in QHttp::qt_metacall () from /usr/lib/libQtNetwork_debug.so.4
#7  0xb79b05b1 in QMetaObject::activate () from /usr/lib/libQtCore_debug.so.4
#8  0xb79b0a2c in QMetaObject::activate () from /usr/lib/libQtCore_debug.so.4
#9  0xb7a68e94 in QAbstractSocket::error () from /usr/lib/libQtNetwork_debug.so.4
#10 0xb7a6b244 in QAbstractSocketPrivate::startConnecting () from /usr/lib/libQtNetwork_debug.so.4
#11 0xb7a6c859 in QAbstractSocket::qt_metacall () from /usr/lib/libQtNetwork_debug.so.4
#12 0xb7a770f2 in QTcpSocket::qt_metacall () from /usr/lib/libQtNetwork_debug.so.4
#13 0xb79af815 in QObject::event () from /usr/lib/libQtCore_debug.so.4
#14 0xb7b4d8b4 in QApplicationPrivate::notify_helper () from /usr/lib/libQtGui_debug.so.4
#15 0xb7b4e8c9 in QApplication::notify () from /usr/lib/libQtGui_debug.so.4
#16 0xb79a444d in QCoreApplication::sendPostedEvents () from /usr/lib/libQtCore_debug.so.4
#17 0xb7bb5711 in QEventDispatcherX11::processEvents () from /usr/lib/libQtGui_debug.so.4
#18 0xb79a1a24 in QEventLoop::processEvents () from /usr/lib/libQtCore_debug.so.4
#19 0xb79a1c76 in QEventLoop::exec () from /usr/lib/libQtCore_debug.so.4
#20 0xb79a4611 in QCoreApplication::exec () from /usr/lib/libQtCore_debug.so.4
#21 0xb7b4d5d7 in QApplication::exec () from /usr/lib/libQtGui_debug.so.4
#22 0x0804d0a3 in main (argc=1, argv=0xbfee1394) at imgtestdialog.cpp:216

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That doesn't help a lot...

Guilugi.

[jacek]

I think that the problem is with:

delete http;
http = 0;

delete http;
http = 0;

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It looks like you delete it while there are still some unprocessed events. Since you call Image::deleteLater(), you could omit those two lines.

[Bojan]

Sorry, i was sick with the flu or cold yesturday so haven't been using the computer. Anyway it looks like you guys solved the problem for me. Indeed if I comment out the delete http lines the code works fine. Kinda weird, didn't really think that could be the problem. Should have tried that maybe before posting I guess. thanks all.

Bojan