insert-buffer is yet another buffer-related function. This
command copies another buffer into the current buffer. It is the
copy-to-buffer, since they
copy a region of text from the current buffer to another buffer.
Here is a discussion based on the original code. The code was simplified in 2003 and is harder to understand.
(See New Body for
insert-buffer, to see
a discussion of the new body.)
In addition, this code illustrates the use of
interactive with a
buffer that might be read-only and the important distinction
between the name of an object and the object actually referred to.