Re: FVWM: Full crash when using an invalid PNG for a mini-icon

Martin Cermak <[email protected]> writes:

> On  Tue  2019-05-28  15:27 , Thomas Adam wrote:
>> On Tue, 28 May 2019 at 14:47, <[email protected]> wrote:
>> >
>> > Hi All,
>> >
>> > I'm using fvwm 2.6.7 from Debian/stretch.
>> >
>> > If I execute the command
>> >
>> >     Pick WindowStyle MiniIcon password.png
>> >
>> > I get a full FVWM crash (and consequently an X server exit + lost work +
>> > tears).
>> 
>> Can you please ensure FVWM has been built with debug symbols, and get
>> a backtrace from gdb?
>
> Reproduced with fvwm-2.6.8-2.fc29.x86_64 (https://koji.fedoraproject.org/koji/buildinfo?buildID=1108778) :
>
> =======
> (gdb) bt
> #0  0x00007ff3879ff53f in raise () from /lib64/libc.so.6
> #1  0x00007ff3879e9895 in abort () from /lib64/libc.so.6
> #2  0x00007ff38851a235 in ?? () from /lib64/libpng16.so.16
> #3  0x00007ff38851f4eb in png_error () from /lib64/libpng16.so.16
> #4  0x00007ff38851f574 in png_chunk_error () from /lib64/libpng16.so.16
> #5  0x00007ff3885325ff in ?? () from /lib64/libpng16.so.16
> #6  0x00007ff388524b08 in png_read_row () from /lib64/libpng16.so.16
> #7  0x00007ff38852668a in png_read_image () from /lib64/libpng16.so.16
> #8 0x0000559b77dc8df1 in PImageLoadPng (dpy=<optimized out>,
> path=<optimized out>, argb_data=0x7ffe4630b2b0, width=<optimized out>,
> height=<optimized out>) at PictureImageLoader.c:535

I'll point out the obvious.

Other programs successfully display that PNG image, some along with an
error message.

In Fvwm's case, libpng calls abort(), because Fvwm hasn't set
up a png error handler.

-- 
Dan Espen