shell as a shell script when the direct execution of the user's
shell failed with ENOEXEC and the user's shell has a shebang. The
interpreter might not be the right one. Executing the user's
shell with sh -c might be better, but I'm not sure we should try
harder when there is a failure. Note: The removed code was only
included #ifndef __linux__.
Files with no license use the default 3-clauses BSD license. The copyright
were mostly not recorded; they were updated according to the Changelog.
"Julianne Frances Haugh and contributors" changed to "copyright holders
and contributors".
