Mark Baushke's fix for command block too long.
In Mark's words:
"Due to a deep tree hierarchy, I was running into the
'fatal error: Clean command block too long (max 10240)'
"I do not believe there should be a fatal error just because the
guess at a chunk size was not a good guess, so I have created a
patch to cmd_new() to return NULL in the event that the text
will not fit into the CMDBUF sized buffer. I have also changed
make1cmds() to notice that cmd_new() returned a NULL and if
possible to adjust the value of chunk until it finds a value
that works. If the smallest possible value (chunk=1) fails,
then it will still generate the fatal error. If chunk starts
out as zero, then no attempt is made to adjust the chunk value
to different sizes, it will just generate a fatal error."