Crash when prepending QString to QList

nicky j

Hello,

whenever I try to run the following code, I get a crash:
@
void NBhistoryInterface::addHistoryItem(QString title, QString url)
{
qDebug() << "SLOT: NBhistoryInterface::addHistoryItem(QString title, QString url) STATUS: Called";
qDebug() << "m_historyTitle.prepend() Called";
m_historyTitle.prepend(title);
qDebug() << "m_historyTitle.prepend() Completed";
qDebug() << "SLOT: NBhistoryInterface::addHistoryItem(QString title, QString url) STATUS: Completed";
}
@
The program launches, then crashes when it gets to the prepend() call. This is becoming a major problem and an obstacle towards moving forward with my project. Here is the crash report provided by OS X 10.9:

@

Exception Type: EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x0000000000000010

VM Regions Near 0x10:
-->
__TEXT 0000000100187000-00000001001b4000 [ 180K] r-x/rwx SM=COW /Users/USER/Desktop/*/NovaBrowser_v2.app/Contents/MacOS/NovaBrowser_v2

Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0 <BUNDLEIDENTIFIER> 0x000000010019eae4 QList<QString>::prepend(QString const&) + 20 (qlist.h:546)
1 <BUNDLEIDENTIFIER> 0x000000010019dec5 NBhistoryInterface::addHistoryItem(QString, QString) + 277 (nbhistory.cpp:29)

@

Help would be appreciated greatly!

andreyc

How is m_historyTitle declared?

nicky j

Thats the first place m_historyTitle is declared in the .cpp file.

andreyc

What is a type of m_historyTitle ?
Are you sure that NBhistoryInterface object is allocated ?

nicky j

ok here is m_historyTitle in the .h file:
@
QList<QString> m_historyTitle;
@

yes NBhistoryInterface is allocated

andreyc

Does you app generate a core file ?
Check /cores/ directory after app crash.
The directory should contain core.PID files.
Could you put here a backtrace.

nicky j

where would i find the cores file?

andreyc

Check /cores/ directory after app crash.
The directory should contain core.PID files.

Chrisw01

Nicky, try running it through the debugger and analyze the data at crash time.