bug#61704: 29.0.60; Crash in get_narrowed_begv

[martin rudalics]

> As a stopgap, how about adding something to the doc strings regarding
> the minimum "safe" values for these "min" variables?  Can you suggest
> such values?  They don't have to be the _absolute_ minima, just safe
> ones.

There are no such values.  These are Lisp constants and code or user
customizations that set their values or bind them are invalid.
Unfortunately, our tools are not strong enough to prevent that.  And a
doc-string that says

  This variable may be risky if used as a file-local variable.

is misleading at the very least.  Maybe we should emphasize in the
documentations the fact that these are constants.

These constants are here so that after we experience a crash with their
specified values, we can fix the code without having to update all their
occurrences.  And they serve in the documentation to say that the values
of the options 'window-min-width' and 'window-min-height' cannot be
effectively less.

martin