xpdf build error: conflicts with new declaration with 'C' linkage

["Jeremy C. Reed" <reed%reedmedia.net@localhost>]

c++ -O2 -I/usr/pkg/include -I/usr/include -I/usr/pkg/include/freetype2 
-DHAVE_CONFIG_H -DPREFIX="\"/usr/pkg\"" -I.. -I./../goo -I./../fofi 
-I./../splash -I. -I/usr/pkg/include/freetype2       -I/usr/pkg/include   
-I/usr/pkg/include -DHAVE_XPDFCORE -c -o SecurityHandler.x.o  SecurityHandler.cc
/home/packages/tmp-pkgsrc/print/xpdf/work.glacier/.buildlink/include/X11/VendorP.h:87:
 error: previous declaration of 'VendorShellClassRec vendorShellClassRec' with 
'C++' linkage
/home/packages/tmp-pkgsrc/print/xpdf/work.glacier/.buildlink/include/Xm/VendorSP.h:58:
 error: conflicts with new declaration with 'C' linkage
*** Error code 1

Stop.

My VendorP.h is from libXt-1.0.5

My VendorSP.h is from lesstif-0.95.0

This is on NetBSD/i386 3.99.24

  Jeremy C. Reed

p.s. I didn't research this yet ...