following a suggestion from him, the way the fix to PR bin/50993
was implemented has changed a little. There are three steps involved
in processing a here document, reading it, parsing it, and then
evaluating it before applying it to the correct file descriptor for
the command to use. The third of those is not related to this
problem, and has not changed. The bug was caused by combining the
first two steps into one (and not doing it correctly - which would be
hard that way.) The fix is to split the first two stages into
separate events. The original fix moved the 2nd stage (parsing)
to just immediately before the 3rd stage (evaluation.) Jilles
pointed out some unwanted side effects from doing it that way, and
suggested moving the 2nd stage to immediately after the first.
This commit makes that change. The effect is to revert the changes
to expand.c and parser.h (which are no longer needed) and simplify
slightly the change to parser.c. (from kre@)
65cf828420