Both unions kept the wrong side. macro_union keeps the left on a name
collision, and both callers had the older set on the left: Load.program
put the ambient set ahead of the packages it had just resolved, and
Session put the copy it had been holding since creation ahead of what
Load handed back. So editing a macro in a package and reloading the file
that imports it went on expanding the old body -- and said nothing,
which in this area is the failure that costs the most to find.
Two tests, because the two unions are reached by different paths: the
reload itself, and the C-c C-c after it, which reads the set the session
kept rather than the one Load just supplied. Each fails on its own if
only the other order is put back.
Also written down, and not fixed: C-x C-e expands no macros at all.
Parse.expr never calls the expander, so (unless ...) as a bare
expression is as much an unknown name as (mac/twice 4) -- the prelude
fails there too, which is what says it is an older gap. Changing it
changes what an expression evaluation means.
And the cost note is cut back to what was measured. Four macro modules
where the file's own macros leave two is what the cache shows; why four
is not settled and no longer claimed.
Joseph Ferano
dd3611f97d