Re: Compiled file behaves differently than the uncompiled file (Was Re: bug#19582)

[David Kastrup <dak@gnu.org>]

Jay Belanger <jay.p.belanger@gmail.com> writes:

> Wolfgang Jenkner <wjenkner@inode.at> writes:
> ...
>> In emacs -Q, do `M-x calc' then convert, say 1m, to cm, i.e.,
>>
>> ' 1 m <return> u c c m <return>
>>
>> This gives `100 cm' on top of the stack (a plain integer scalar).
>>
>> Next, start another emacs -Q instance, do `M-x calc' and then, before
>> anything else, `M-: (load-library "calc-units")'.
>>
>> Now the same conversion exercise as before gives `100. cm' on the stack
>> instead (a calc float).
>
> The float appears because Calc does units simplifications differently if the
> calc-units.elc file is loaded too soon.  I'm not sure why.  I could
> probably narrow the problem down a little more, but not too far since
> the problem is in the elc file, not the el file.
>
> If the calc-units.elc file is loaded when it is supposed to be, the
> float doesn't
> appear.
> If the calc-units.elc file is loaded right away, then the float appears.
> If the calc-units.el file is loaded right away, then the float doesn't appear.
>
> What could cause the elc file to behave differently than the el file?

One obvious candidate is
(eval-when-compile
  (require 'calc-alg))

This will _not_ be loaded by calc-unit.elc, but it will be loaded by
calc-unit.el.

So try loading it before calc-unit.elc and see whether that makes a
difference.

-- 
David Kastrup