Memory leaks with QDomElement::tagName()

[saracaeus]

Hello,

this is the scenario:
- VStudio2005, using Qt4.7.2, built for VS2005 (dumpbin -imports on the Qt libs refering to VS80 libs)
- I build another dll which links QtXml4.dll

THIS method is creating memory leaks:

int CTestClass::blubber( int iBlubber )
{
  QDomElement aRoot;
  aRoot.tagName();
  return 0;
}

int CTestClass::blubber( int iBlubber )
{
  QDomElement aRoot;
  aRoot.tagName();
  return 0;
}

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and THE SAME method with commented tagName() is NOT creating memory leaks:

int ARGOSXml_DomParser::blubber( int iBlubber )
{
  QDomElement aRoot;
//  aRoot.tagName();
  return 0;
}

int ARGOSXml_DomParser::blubber( int iBlubber )
{
  QDomElement aRoot;
//  aRoot.tagName();
  return 0;
}

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NOTE: I do NOT call this method! just linking!

I am really helpless... perhaps anyone got an idea!

If you need more information, please ask!

Any help is appreciated!
saracaeus

[Lykurg]

How do you measure that it is a memory leak? I can't see it.

[wysota]

This is how this method is implemented:

QString QDomElement::tagName() const
{
    if (!impl)
        return QString();
    return impl->nodeName();
}

QString QDomElement::tagName() const
{
    if (!impl)
        return QString();
    return impl->nodeName();
}

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I don't see where it could possibly leak memory.

[saracaeus]

well, thats exactly why I am helpless... I have no clue... the memory leaks coming from VS2005, this is the output:

Detected memory leaks!
Dumping objects ->
{220} normal block at 0x012F4550, 24 bytes long.
 Data: <                > 00 CD CD CD 00 00 00 00 00 00 00 00 00 00 00 00 
{219} normal block at 0x012F44F0, 32 bytes long.
 Data: <                > 01 00 00 00 03 00 00 00 00 00 00 00 01 00 00 00 
{218} normal block at 0x012F44B0, 4 bytes long.
 Data: < D/ > F0 44 2F 01 
{217} normal block at 0x012F4458, 24 bytes long.
 Data: <                > 00 CD CD CD 00 00 00 00 00 00 00 00 00 00 00 00 
{216} normal block at 0x012F4410, 12 bytes long.
 Data: <XD/   ;g  ;g> 58 44 2F 01 C8 DD 3B 67 C8 DD 3B 67 
{215} normal block at 0x012F43B8, 24 bytes long.
 Data: <                > 00 CD CD CD 00 00 00 00 00 00 00 00 00 00 00 00 
{214} normal block at 0x012F4370, 12 bytes long.
 Data: < C/   ;g  ;g> B8 43 2F 01 C8 DD 3B 67 C8 DD 3B 67 
{213} normal block at 0x012F4318, 24 bytes long.
 Data: <                > 00 CD CD CD 00 00 00 00 00 00 00 00 00 00 00 00 
{212} normal block at 0x012F42B8, 36 bytes long.
 Data: < C/ pC/  D/     > 18 43 2F 01 70 43 2F 01 10 44 2F 01 00 00 00 00 
{211} normal block at 0x012F4278, 4 bytes long.
 Data: < B/ > B8 42 2F 01 
{210} normal block at 0x012F4238, 4 bytes long.
 Data: < Y.g> A8 59 2E 67 
Object dump complete.
The thread 'Win32 Thread' (0x814) has exited with code 0 (0x0).

Detected memory leaks!
Dumping objects ->
{220} normal block at 0x012F4550, 24 bytes long.
 Data: <                > 00 CD CD CD 00 00 00 00 00 00 00 00 00 00 00 00 
{219} normal block at 0x012F44F0, 32 bytes long.
 Data: <                > 01 00 00 00 03 00 00 00 00 00 00 00 01 00 00 00 
{218} normal block at 0x012F44B0, 4 bytes long.
 Data: < D/ > F0 44 2F 01 
{217} normal block at 0x012F4458, 24 bytes long.
 Data: <                > 00 CD CD CD 00 00 00 00 00 00 00 00 00 00 00 00 
{216} normal block at 0x012F4410, 12 bytes long.
 Data: <XD/   ;g  ;g> 58 44 2F 01 C8 DD 3B 67 C8 DD 3B 67 
{215} normal block at 0x012F43B8, 24 bytes long.
 Data: <                > 00 CD CD CD 00 00 00 00 00 00 00 00 00 00 00 00 
{214} normal block at 0x012F4370, 12 bytes long.
 Data: < C/   ;g  ;g> B8 43 2F 01 C8 DD 3B 67 C8 DD 3B 67 
{213} normal block at 0x012F4318, 24 bytes long.
 Data: <                > 00 CD CD CD 00 00 00 00 00 00 00 00 00 00 00 00 
{212} normal block at 0x012F42B8, 36 bytes long.
 Data: < C/ pC/  D/     > 18 43 2F 01 70 43 2F 01 10 44 2F 01 00 00 00 00 
{211} normal block at 0x012F4278, 4 bytes long.
 Data: < B/ > B8 42 2F 01 
{210} normal block at 0x012F4238, 4 bytes long.
 Data: < Y.g> A8 59 2E 67 
Object dump complete.
The thread 'Win32 Thread' (0x814) has exited with code 0 (0x0).

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And as I noted: the method is NOT even called!

And once i comment this line, the memory leaks are gone!

[wysota]

When is that "leak" reported? If the method is not called, it can't possibly create a memory leak. If you have a leak then it is elsewhere.