Undefined behavior isn't limited to from that point on, it can have terribly surprising consequences.
A great example at: http://blogs.msdn.com/b/oldnewthing/archive/2014/06/27/10537...
Re:Proposal for a Friendly Dialect of C
by readerrrr on Wednesday August 27, 2014 @03:57PM
(#8234416)
You misinterpreted my statement. From that point on means when you code it.
I have read that article before; the usage of the word time travel is nonsense. Author could just as well say the code preceding the ub can get mangled and avoid confusion.
Undefined behaviour means anything can happen from that point on( bad ), while unspecified just gives you an unspecified value.
3. Again unspecified vs. undefined.
1. From C11 Standard: The value of a pointer becomes indeterminate when the object it points to (or just past) reaches the end of its lifetime. When you use that pointer you get undefined b.