[Gimp-print-devel] [Patch] gutenprint53+usb crashes with libusb-1.0.25

[Zdenek D. <zd...@re...>]

Hi all,

there were changes in libusb 1.0.25 which is in Fedora 36 - f.e. default 
USB context is not initialized unless you specifically pass NULL into 
`libusb_init()` - gutenprint53+usb backend actually depended on this 
hidden behavior, because it passes its own context address into 
`libusb_init()` instead of NULL. So the change causes the backend to 
crash if you run it:

=======================================

$ sudo /usr/lib/cups/backend/gutenprint53+usb

DEBUG: Multi-Call Dye-sublimation CUPS Backend version 0.110G
DEBUG: Copyright 2007-2020 Solomon Peachy
DEBUG: This free software comes with ABSOLUTELY NO WARRANTY!
DEBUG: Licensed under the GNU GPL.  Run with '-G' for more details.

...

DEBUG:         [ -R ]           # Reset printer
DEBUG:         [ -s ]           # Query printer status
STATE: +org.gutenprint.searching-for-device
Segmentation fault

========================================

The backtrace is available in the related bugzilla [1].

According libusb maintainer, Ben Berg, the backend can work with the 
default USB context and he prepared the patch for it (the file is 
attached). I was able to verify the patch fixes the crash, but I don't 
have a device supported by gutenprint itself, so I couldn't do an 
additional sanity testing. The patch looks good to me though.

Would you mind adding the patch to the project if it looks good for you?


Thank you in advance!


Zdenek


[1] https://bugzilla.redhat.com/show_bug.cgi?id=2055504

-- 
Zdenek Dohnal
Software Engineer
Red Hat, BRQ-TPBC