BUG: coxpcall returns the error message twice

[Tieske]

This line:

coxpcall/src/coxpcall.lua

Line 47 in 732898e

return false, err(debug.traceback(co, (...)), ...)

as part of this function;

coxpcall/src/coxpcall.lua

Lines 45 to 48 in 732898e

	function handleReturnValue(err, co, status, ...)
	if not status then
	return false, err(debug.traceback(co, (...)), ...)
	end

The vararg (...) is the result of the function called in protected mode. If that fails with an error "error", the result will become;

	false, "error+stacktrace", "error"

So the error is being returned twice, or more precisely all error results will be shifted by 1.

Since this bug has been in here for ages, and Lua 5.1 is getting obsolete, I'm not providing a PR, just this issue to document it.