lib/53080: fontconfig causes segfault on NetBSD 8.0_BETA

[dogan%tesmer.org.tr@localhost]

>Number:         53080
>Category:       lib
>Synopsis:       fontconfig causes segfault on NetBSD 8.0_BETA
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    lib-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Mar 08 09:05:00 +0000 2018
>Originator:     Mustafa Dogan
>Release:        NetBSD 8.0_BETA
>Organization:
TESMER
>Environment:
NetBSD localhost 8.0_BETA NetBSD 8.0_BETA (GENERIC) #0: Thu Mar  8 04:35:26 UTC 2018 root@localhost:/usr/src/sys/arch/amd64/compile/GENERIC amd64
>Description:
I make build weekly NetBSD 8 source tree. Last two build have X11 problem related to fontconfig. X11 applications don't work (due to fontconfig dependency).
I make fresh build (by deleting OBJ and TOOLS folders), installed and rebooted. While booting, /etc/rc.d/fccache (in fact, /usr/X11R7/bin/fc-cache) failed with segmentation fault. I backtraced with gdb and results are below:

Reading symbols from /usr/X11R7/bin/fc-cache...(no debugging symbols found)...done.
[New process 1]
Core was generated by `fc-cache'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  0x000074205f60f289 in ?? () from /usr/X11R7/lib/libfontconfig.so.2
(gdb) bt
#0  0x000074205f60f289 in ?? () from /usr/X11R7/lib/libfontconfig.so.2
#1  0x000074205f610511 in FcPatternObjectGet () from /usr/X11R7/lib/libfontconfig.so.2
#2  0x000074205f610699 in FcPatternObjectGetString () from /usr/X11R7/lib/libfontconfig.so.2
#3  0x000074205f61d54d in FcConfigAddCache () from /usr/X11R7/lib/libfontconfig.so.2
#4  0x000074205f61d696 in ?? () from /usr/X11R7/lib/libfontconfig.so.2
#5  0x000074205f61d71d in IA__FcConfigBuildFonts () from /usr/X11R7/lib/libfontconfig.so.2
#6  0x000074205f61d79c in IA__FcConfigSetCurrent () from /usr/X11R7/lib/libfontconfig.so.2
#7  0x000000012f601e84 in main ()

>How-To-Repeat:
run /usr/X11R7/bin/fc-cache
>Fix: