Review Request: Make TGAHandler to be stricter about supported files, makes Konqueror not to crash on http://www.hs.fi

[Teemu Rytilahti]

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Review request for kdelibs.


Summary
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Update kimgio's TGAHandler to be stricter about whether the file is supported or not + removes duplicate checks. Changes are based on the spec which can be found from here: http://www.ludorg.net/amnesia/TGA_File_Format_Spec.html

See the attached bugs for possible casualties of the not-so-strict checking, and you can also test http://www.hs.fi with Konqueror.

For a simpler test-case with Konqueror, try putting '<link href="http://www.hs.fi/static/hs3/css/hs-compressed.css" rel="stylesheet" type="text/css" media="all" />' to an HTML file and load it up on Konqueror, due to an empty url() in that CSS file, Konqueror/KHTML tries to find out who wants to load the file with an empty url and apparently goes through QImageIO to see if someone supports that data, TGAHandler's canRead() reports true and call to LoadTGA is made. That doesn't check whether the input is valid and kaboom, it crashes.


This addresses bugs 189338 and 192191.
    https://bugs.kde.org/show_bug.cgi?id=189338
    https://bugs.kde.org/show_bug.cgi?id=192191


Diffs
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  /trunk/KDE/kdelibs/kimgio/tga.cpp 969090 

Diff: http://reviewboard.kde.org/r/756/diff


Testing
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Tested by using images from this site: http://www.fileformat.info/format/tga/sample/index.htm . Two of the 8-bit images do not work, but they did not do that earlier either. http://www.hs.fi does not crash anymore either.


Thanks,

Teemu