Things that work in bash-5.0 but not work in bash-5.1-rc1

[Hyunho Cho]

< bash-5.0 >

$ read rows cols < <(stty size)

$ echo $rows $cols
19 95

< bash-5.1-rc1 >

$ read rows cols < <(stty size)
stty: 'standard input': Inappropriate ioctl for device

$ echo $rows $cols
                                   <---- empty

-------------------------------------------------------

< bash-5.0 >

# emacs start with contents of ls command output
$ ls | emacs < /dev/tty --insert <(cat)

< bash-5.1-rc1 >

# emacs does not start with contents of ls command output
$ ls | emacs < /dev/tty --insert <(cat)

-------------------------------------------------------

< bash-5.0 >

$ ( trap 'uname' CHLD; date )
Wed Oct  7 16:39:55 KST 2020
Linux

< bash-5.1-rc1 >

$ ( trap 'uname' CHLD; date )           # some strange warning messages appear
Wed Oct  7 16:40:05 KST 2020
Linux
bash: warning: run_pending_traps: recursive invocation while running
trap for signal 17