🚀 go-pugleaf

The ditroff (aka troff) in Documenter's WorkBench 2.0 core dumps
when a break and some text follow a \D draw command.  For example,
this input causes a core dump:

	\D'c 1i'
	.br
	a

Here is a fix, courtesy of Henry McGilton.  The core dump is caused
by an attempt to store a value in a negative (out-of-bounds) array
location.  The core dump actually occurs in the getcw() function,
although the bug is in the ptout0() function.  Note that only two
lines need to be added; lines marked ! are just indented further.

*** 302,313 ****
        if (k < 040 && k != DRAWFCN)
                return(outsize);
!       if (widcache[k-32].fontpts == (xfont<<8) + xpts  && !setwdf) {
!               w = widcache[k-32].width;
!               bd = 0;
!               cs = 0;
!       } else 
!               w = getcw(k-32);
        j = z = 0;
        if (k != DRAWFCN) {
--- 304,317 ----
        if (k < 040 && k != DRAWFCN)
                return(outsize);
+       if (k >= 32) {
!               if (widcache[k-32].fontpts == (xfont<<8) + xpts  && !setwdf) {
!                       w = widcache[k-32].width;
!                       bd = 0;
!                       cs = 0;
!               } else
!                       w = getcw(k-32);
+       }
        j = z = 0;
        if (k != DRAWFCN) {

The ditroff in DWB 1.0 has the same bug, but does not core dump
with the input given above because it tests, but does not store a
value in, the out-of-bounds array location.

Bill Tuthill