On Sat, Jan 09, 2021 at 12:05:31AM -0800, William Ahern wrote:
<snip>
> Interestingly, DragonflyBSD and FreeBSD already do it this way[3][4], yet I
> can confirm FreeBSD still has the problem. (DragonflyBSD has nearly
> identical code.) But that implementation duplicates the short-circuit, along
> with the bug of not accounting for skip1 and skip2, in cmp.c as part of
> implementing the -z flag[5]:
>
> if (special)
> c_special(fd1, file1, skip1, fd2, file2, skip2);
> else {
> if (zflag && sb1.st_size != sb2.st_size) {
> if (!sflag)
> (void) printf("%s %s differ: size\n",
> file1, file2);
> exit(DIFF_EXIT);
> }
> c_regular(fd1, file1, skip1, sb1.st_size,
> fd2, file2, skip2, sb2.st_size);
> }
> exit(0);
>
> It appears that the June 20, 2000 fix to the short-circuit in regular.c
> wasn't recognized during the July 14, 2000 -z feature addition.[6][7]
Note that zflag is set with sflag earlier in FreeBSD's regular.c:
case 's': /* silent run */
sflag = 1;
zflag = 1;
break;
