Re: erroneous byte-compilation during build process?

[Richard Stallman]

I am going through messages which I failed to handle during the past
year, and came across yours.

      Because of this, it occurred to me that the error might not
    be in recentf.el but in recentf.elc.  So I made a fresh
    byte-compilation of the source file and copied it to the install
    directory and loaded recentf, making sure the conditions that give
    rise to error were satisfied, and sure enough, the error failed to
    occur.  Then I reinstalled the original byte-compiled file and
    repeated the test, and got the error again.  So I conclude that the
    recentf.elc made by building Emacs is somehow erroneous.

Does this still happen?  Can you make it happen?  Did we ever make a
change that should have fixed it?

It is clear that there was a miscompilation.  There's a difference in
the bytecode of the two versions of the function recentf-open-files,
as well as in the arguments.  I think that the function 
tree-widget-set-theme got open coded in one of the two versions
but was called with a function call in the other.