[ REQ 6925]: Geomview bug

[michiel_uitdehaag at tasking.nl]

Hi,

I've downloaded Geomview 1.6.1 yesterday and finally managed to compile
it.

I found that the variable _Xsetlocale was unreferenced by gvx and
animate . I've added the variable definition to window.h, so that gvx
would compile, but animate still does not compile.

However, I've encountered the following bug:
startup gvx with
geomview tetra dodec

Then select NDDemo from the External Modules list. Slide the motion bar
up and the point will start to move in 4D space. 
With the optimized binary, it would crash at the -Y_MAX point. With the
debug version, it would crash after one or two circles.

The crash is located in meshnormal.c:151:
Program received signal SIGSEGV, Segmentation fault.
0x8086821 in mnorm (ap=0x8320fb0, an=0x8320f78, nu=2, nv=2, uwrap=0,
vwrap=0, 
    evert=0) at meshnormal.c:151
151                                 n->x = (cur+1)->x - (cur-1)->x;

(gdb) bt
#0  0x8086821 in mnorm (ap=0x8320fb0, an=0x8320f78, nu=2, nv=2, uwrap=0, 
    vwrap=0, evert=0) at meshnormal.c:151
#1  0x808632c in MeshComputeNormals (m=0xbffff03c) at meshnormal.c:34
#2  0x8088176 in draw_projected_mesh (NDmap=0x8065008 <map_ND_point>, 
    NDinfo=0xbffff580, mesh=0x82f6978) at meshdraw.c:38
#3  0x80883e8 in MeshDraw (mesh=0x82f6978) at meshdraw.c:78
#4  0x8079e1e in GeomDraw (object=0x82f6978) at draw.c:26
#5  0x808cbb1 in ListDraw (list=0x82f68b0) at listdraw.c:22
#6  0x8079e1e in GeomDraw (object=0x82f68b0) at draw.c:26
#7  0x808cbb1 in ListDraw (list=0x82fdfd0) at listdraw.c:22
#8  0x8079e1e in GeomDraw (object=0x82fdfd0) at draw.c:26
#9  0x808a587 in InstDraw (inst=0x82fe120) at instdraw.c:146
#10 0x8079e1e in GeomDraw (object=0x82fe120) at draw.c:26
#11 0x808a587 in InstDraw (inst=0x82fe1b0) at instdraw.c:146
#12 0x8079e1e in GeomDraw (object=0x82fe1b0) at draw.c:26
#13 0x8059dcf in really_draw_view (dv=0x82d72a0) at drawer.c:2801
#14 0x805968d in draw_view (dv=0x82d72a0) at drawer.c:2648
#15 0x8054bbd in Ldraw (lake=0x0, args=0x82fe688) at drawer.c:657
#16 0x80dc901 in LEval (obj=0x830e9e8) at lisp.c:1042
#17 0x80dd70b in LEvalFunc (name=0x81dadcd "draw") at lisp.c:1437
#18 0x806109a in gv_draw (a1=-2) at ../clang.c:198
#19 0x8054b20 in Lupdate_draw (lake=0x0, args=0x8301878) at drawer.c:640
#20 0x80dc901 in LEval (obj=0x82f3728) at lisp.c:1042
#21 0x80dd70b in LEvalFunc (name=0x81dadc1 "update-draw") at lisp.c:1437
#22 0x8061064 in gv_update_draw (a1=-2, a2=0) at ../clang.c:189
#23 0x8077354 in main_loop () at gvevent.c:128
#24 0x806ffae in main (argc=3, argv=0xbffff854) at gvmain.c:69

an if statement just above that line tests for k==nu and increments cur
if k==nu.
In this case k==nu and cur is incremented above the array top (cur+1 is
the violator).

Hope this helps. Thanks for a wonderful product by the way. Now that it
compiles, it works like a charm for the rest.

Michiel Uitdehaag
Software Engineer