Re: insert-file-contents and fifos

[Richard Stallman]

    GNU emacs 20 was capable of reading from this, 21 is not. The change
    appears to be the introduction of the new read_non_regular function
    in fileio.c : a strace shows emacs fetching the data from the file
    ( you can see the data being read ), and then aborting. Presumably
    the state of a fifo is sufficiently different from a non-regular file
    that read_non_regular reacts as if an error has occurred.

Could you step through it and see why this happens?
The code looks straightforward, so I don't see why it would fail.