static int
name_is_acceptable (name)
     const char *name;
{
  struct ign *p;
  int nlen;

  for (nlen = strlen (name), p = fignore.ignores; p->val; p++)
    {
      if (nlen > p->len && p->len > 0 && STREQ (p->val, &name[nlen - p->len]))
        return (0);
    }

  return (1);
}

Note that the length of the path being checked must be greater than the length of the item in FIGNORE. So FIGNORE=.svn will not reject an entry that is just .svn

The catch is that leading path components are considered as part of the name. Example:
% ls <tab>
Breakpoint 1, name_is_acceptable (name=0x71d510 ".svn") at bashline.c:2536

% ls ./<tab>
Breakpoint 1, name_is_acceptable (name=0x73dcb0 "./.svn") at bashline.c:2536

So, FIGNORE=.svn will only ignore the directory .svn when there are leading path components.

% export FIGNORE=svn
% ls ./<tab>
svn-test/ test/