Change Details

Having `a.size()==0` and then access `a[0]` is undefined behavior. Add Span::empty() and use it in script/descriptor This is a backport of core#19508

Having `a.size()==0` and then access `a[0]` is undefined behavior. Add Span::empty() and use it in script/descriptor This is a backport of [[https://github.com/bitcoin/bitcoin/pull/19508 | core#19508]]

Having `a.size()==0` and then access `a[0]` is undefined behavior. Add Span::empty() and use it in script/descriptor This is a backport of [[https://github.com/bitcoin/bitcoin/pull/19508 | core#19508]]