srfi-42: append-ec fails when apply limit is reached

[acharlton]

Which causes simple operations like this to fail:

(append-ec (: i 10000)
           (list i i))

Attached is a patch that fixes this issue.

This issue is also present in string-append-ec, but a similar, reasonably efficient fix would involve adding a dependancy of some sort. Probably the easiest way would be to use srfi-13 and replace (apply string-append ...) with (string-concatenate ...)

[sjamaan]

Should be fixed with #1098, but the attached patch might also do the trick. Ivan, can you take a look at the patch?

[Ivan Raikov]

It looks like I had applied the patch and made a new release back in December, but I had forgotten to close this ticket.