XMLDocument destructor crashes in DEBUG build about tinyxml2 HOT 4 CLOSED

The code, as sent, crashes because of this:

    XMLNode* settings = xmlDoc->FirstChildElement("s");

The root element of the xmlDoc is "settings" not "s". I'm not sure why you see the assertion crash and not this; if the test isn't correct, I'd appreciate an update. Here's the test code I'm using:

    {
        const char* xml = "<settings>"
                                "<entry name=\"stringvalue\" type=\"s\" value=\"version1 string\" />"
                                "<entry name=\"intvalue\" type=\"i\" value=\"125\" />"
                                "<entry name=\"floatvalue\" type=\"f\" value=\"3.1415\" />"
                            "</settings>";
        XMLDocument *xmlDoc = new XMLDocument();

        //xmlDoc->LoadFile("config1.cfg");
        xmlDoc->Parse( xml );
        xmlDoc->Print();

        XMLNode* settings = xmlDoc->FirstChildElement("s");

        const char *versionString = settings->ToElement()->Attribute("version");
        printf("version: %s", versionString ? versionString : "");

        delete xmlDoc; // crashes here - XMLDocument destructor

    }

from tinyxml2.

Thanks Lee for the quick answer. It turns out that my example code was incorrect because I was focusing on the wrong place. Here's the one that triggers the issue:

#include "tinyxml2.h"
using namespace tinyxml2;

int main()
{
    {
        XMLDocument xmlDoc;

        xmlDoc.NewDeclaration();
        xmlDoc.NewComment("teasing you");
    } // <-- assert happens here...

    return 0;
}

I know that this code is grammatically incorrect (creation of a new elements without using them i.e. Declaration and Comment elements created but not added somewhere) but this should pass anyway (i.e. I can create any number of Declarations without using them in the document).

from tinyxml2.

The bug is non-destructive: what happens is that the nodes aren't added to
the tree, and the assert is firing because they haven't been deleted by a
walk of the tree.

The good news: The memory will get cleaned up. The "crash" is a mis-firing
assert, as you noted.
The annoying part: The assert isn't correct. I don't want to lose the
assert on an actual memory leak, but this isn't one.

Working on a fix.

lee

On Mon, Oct 22, 2012 at 12:55 PM, Daniel Kolakowski <
[email protected]> wrote:

Thanks Lee for the quick response. My code was incorrect to reproduce the
core of the issue. Here's the one to do it:
#include "tinyxml2.h"
using namespace tinyxml2;

int main()
{
{
XMLDocument xmlDoc;

xmlDoc.NewDeclaration();
xmlDoc.NewComment("Configuration file");

XMLElement *root = xmlDoc.NewElement("settings");
root->SetAttribute("version", 2);

}

return 0;

}

—
Reply to this email directly or view it on GitHubhttps://github.com//issues/75#issuecomment-9678068.

from tinyxml2.

Just checked in what I hope is a fix. (It's more delicate code than I would like.) If you allocate memory you don't use, but which will get cleaned up, it should no longer assert.

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