background, pipeline, hang

[Mike Jonkmans]

Configuration Information [Automatically generated, do not change]:
Machine: x86_64
OS: linux-gnu
Compiler: gcc
Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='x86_64' 
-DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='x86_64-pc-linux-gnu' 
-DCONF_VENDOR='pc' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash' -DSHELL 
-DHAVE_CONFIG_H   -I.  -I../. -I.././include -I.././lib  -Wdate-time 
-D_FORTIFY_SOURCE=2 -g -O2 -fdebug-prefix-map=/build/bash-N2nMjo/bash-4.4.18=. 
-fstack-protector-strong -Wformat -Werror=format-security -Wall 
-Wno-parentheses -Wno-format-security
uname output: Linux sint 4.15.0-54-generic #58-Ubuntu SMP Mon Jun 24 10:55:24 
UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
Machine Type: x86_64-pc-linux-gnu

Bash Version: 4.4
Patch Level: 20
Release Status: release

Description:
        A pipeline, with two or more pipes, hangs when a background job is 
running.
        Only when the background job finishes, the shell prompts again.
        Without the background job, the shell prompts immediately.

Repeat-By:
        : | : | : ## immediately finishes
        sleep 10 &
        : | : | : ## this hangs (^C, ^\, ^Z do not help) until the sleep 
finishes

Regards, Mike