Should 'signal' sometimes return?

[Paul Eggert]

Bug#24047 proposes changing Elisp's 'signal' function to not return. 
Although this has been the documented behavior for decades, apparently 
there has been a back door in 'signal' for nearly as long, which causes 
'signal' to return sometimes under control of the Elisp debugger. The 
proposal is to remove this backdoor. If this proposed change to Emacs 
would cause problems for you, please send email to 
address@hidden Thanks.

http://bugs.gnu.org/24047