[Gimp-developer] Crash with Print simulation

[Elle Stone <ellestone ninedegreesbelow com>]

With current GIMP from git (last updated yesterday), "Preferences/Color 
Management/Print simulation" is sometimes very slow to refresh the 
screen, even with small (900x600px) images, and will sometimes crash GIMP.

The last time I used GIMP 2.9's Print simulation was in April 2015, 
using LCMS 2.7, on a ten-year-old AMD Opteron computer, running Gentoo, 
with opencl disabled, at which point the Print simulation was "a bit" 
slow but very useable on images roughly 2000px by 3000px. I'm still 
running Gentoo, but using LCMS 2.8 from git updated about a month ago, 
on a new Intel i7 computer, with opencl enabled. So I'm not sure whether 
this is a GIMP bug, an LCMS bug, an "incompatible with current hardware" 
bug, a dependencies version problem, or etc.

The Color Management Preferences combination that sometimes causes a 
crash seems to be:

1. Open or make a floating point sRGB image with out of gamut RGB values.
     As an aside, out of gamut RGB values generate screenfuls of 
terminal messages like the following:
(gimp-2.9:23822): GLib-GObject-WARNING **: value "((GimpRGB*) 
0x3664030)" of type 'GimpRGB' is invalid or out of range for property 
'color' of type 'GimpRGB'. These terminal messages are not usually 
accompanied by GIMP crashing.

2. Under "Edit/Preferences/Color Management/Print simulation profile" 
choose an RGB profile that is of the "LUT" type rather than a simple 
matrix RGB profile. The "Softproof rendering intent"  doesn't matter, 
and it doesn't matter whether using or not using black point compensation.

3. Select "Mark out of gamut colors". This is what triggers the crash, 
but only when combined with 1. and 2., and even then, not always.

Here is an XCF file that triggers the crash. In the bottom layer all the 
colors in gamut with respect to the sRGB color gamut; in the second 
layer some of the colors are out of gamut: 
http://ninedegreesbelow.com/bug-reports/gimp29/red-green-blue-glass.xcf

I don't have any LUT RGB profiles that permit redistribution, so here 
are links to web pages where such profiles can be downloaded:
http://www.drycreekphoto.com/icc/Profiles/IccFiles/NewYork/MPL-Chromira-Matte.icc
http://media.ephotopros.com/fromex/Fromex_Fuji_Pearl.icc
http://www.color.org/srgbprofiles.xalter#v4pref - choose the "sRGB v4 
Preference" profile, which despite the glowing verbiage makes a truly 
terrible RGB working space profile, as it is a LUT profile that isn't 
color-balanced.

Oddly enough, this much older LUT profile doesn't seem to cause a crash: 
http://rpm.pbone.net/index.php3/stat/26/dist/46/size/113654/name/PhotoGamutRGB-1.0-15.3.src.rpm 
(extract the src, then extract the profile).

Can anyone confirm the crash and/or have any idea why GIMP is crashing?

Best regards,
Elle
--
http://ninedegreesbelow.com
Color management and free/libre photography