[Qt-interest] Bug in QString::section with QRegExp and SectionIncludeLeadingSep

[Markus Wagner]

Hi all,

I am not sure if I found a bug, or if the crash is "defined" behaviour.

When using

QString section ( const QRegExp & reg, int start, int end = -1,  
SectionFlags flags = SectionDefault ) const

with QString::SectionIncludeLeadingSep as flags and accessing an  
element which is non-existing (e.g. start=1 and end=1, where the reg  
will result in only a single result), the method call will crash; see  
example code below.
Expected behaviour would be to retrive an empty or null string.

Should I file a bug report, or am I missing something?!

Greetings, Markus

===== Example-code:=====

#include <QtCore/QCoreApplication>
#include <QtCore/QRegExp>
#include <QtCore/QString>

int main(int argc, char *argv[])
{
     QCoreApplication a(argc, argv);

     QString splitMe1 = "A1234 B5678";
     QString splitMe2 = "99.0 42.3";

     QRegExp rx("\\s*[AaBb]\\s*");

     QString split;

     split = splitMe1.section(rx,0,0,QString::SectionIncludeLeadingSep);
     qDebug(split.toAscii().data()); // empty string

     split = splitMe1.section(rx,1,1,QString::SectionIncludeLeadingSep);
     qDebug(split.toAscii().data()); // "A1234"

     split = splitMe1.section(rx,2,2,QString::SectionIncludeLeadingSep);
     qDebug(split.toAscii().data()); // " B5678"

     split = splitMe2.section(rx,0,0,QString::SectionIncludeLeadingSep);
     qDebug(split.toAscii().data()); // "99.0 42.3"

     split =  
splitMe2.section(rx,1,1,QString::SectionIncludeLeadingSep); // crash -  
expecting at least an empty string
     if (!split.isNull())
         qDebug(split.toAscii().data());

     return a.exec();
}



-- 
Markus Wagner
Römerstraße 39
64291 Darmstadt
markus at mwagner.info
+49-6151-3929440
+49-179-5481432