Eric Blake wrote: > This change needs to be incorporated upstream in gnulib (cc'd); from > there it will find its way into the next m4 release.
What compiler is being used, and what macros does this compiler predefine? More generally: Why is the change needed? What happens, exactly, if you don't have the change? The VAX doesn't have NaNs at all, right? So that section of code shouldn't be compiled at all: isnan should simply return 0 without inspecting its argument. That is the real bug that needs to get fixed here.
