7229 – XGetExtensionVersion return value misinterpreted causing segmentation fault when an extension is not found

XGetExtensionVersion return value misinterpreted causing segmentation fault w...

Status:

RESOLVED: FIXED

Priority:
Medium

Severity:
normal

Product:
Xfce4-settings

Component:

Settings Helper

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Description SP 2011-02-03 05:36:45 CET

In the code snippet below the "version" pointer value is compared against NULL when it should be compared against NoSuchExtension (defined as "1" and not "0" in XI.h).

I'm using libXi 1.4.1 and xfce-settings 4.8.1

    /* query the extension version */
    version = XGetExtensionVersion (xdisplay, INAME);

    /* check for Xi */
        printf("-->%p %d\n", version, version);
    if (version == NoSuchExtension || !version->present)

Comment 1 Jérôme Guelfucci editbugs

2011-02-03 18:03:58 CET

I just pushed a fix for this. This were a little bit complex: you need to check for NULL then you can cast to a long to compare to NoSuchExtension. Thanks for pointing this problem out.

Comment 2 Nick Schermer editbugs

2011-02-05 23:14:59 CET

You never pushed this I think, at least, I don't see the commit.

Comment 3 Jérôme Guelfucci editbugs

2011-02-05 23:39:09 CET

Yeah, thanks for spotting this. Just actually pushed.

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Bug #7229

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