Re: Avoiding 'with-temp-buffer' in tight loops

[martin rudalics <rudalics@gmx.at>]

 >> Ever since 'substitute-command-keys' has been transferred to help.el,
 >> putting initial breakpoints in Fkill_buffer has become virtually
 >> impossible.
 >
 > It should be possible to make the breakpoint conditional on the first
 > character of a temporary buffer not being SPC.

This fails when investigating a general misbehavior of 'kill-buffer'
that might also happen when the buffer name starts with a space.  And it
won't catch the case where such a buffer is killed inadvertently as
"current buffer".

 > This needs to be amended to support several threads calling
 > substitute-command-keys, I think.

Protecting access to any such buffer with the help of a mutex should be
trivial.  But IIUC we don't do such a thing anywhere and it's certainly
not done with Vprin1_to_string_buffer which was used earlier for this
purpose.  So my faith in the correct resolution of locks is limited.

 > An alternative for the above is to have substitute-command-keys bind
 > some variable non-nil, and have a breakpoint be conditional on that
 > variable's value.  If this works, I think it's simpler and cleaner.

This means that every tight loop using 'with-temp-buffer' would have to
set up and clear that variable.  It would fail to catch all cases where
killing a buffer associated with that variable is the cause of the
problem to fix.

martin