bash-5.0: case command bug

[Drab Martin]

Hi,

I have a problem with bash 5.0:

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machine1 ~ # bash --version
GNU bash, version 5.0.0(1)-release (x86_64-pc-linux-gnu)
Copyright (C) 2019 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>

This is free software; you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

machine1 ~ # case "a-b" in *-*-*) echo "This is a BUG" ;; *) echo "This is not a 
BUG" ;; esac
This is a BUG
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as opposed to bash 4:

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machine2 ~ # bash --version
GNU bash, version 4.4.23(1)-release (x86_64-pc-linux-gnu)
Copyright (C) 2016 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>

This is free software; you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

machine2 ~ # case "a-b" in *-*-*) echo "This is a BUG" ;; *) echo "This is not a 
BUG" ;; esac
This is not a BUG
-----

Is it a bug or a feature? Because for me it completely crippled Gentoo compilation system, as the config.sub does not 
work correctly anymore. Which in turn means that any automake building does not work as it results to:

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machine1 ~ # /usr/share/gnuconfig/config.sub x86_64-pc-linux-gnu
Invalid configuration `x86_64-pc-linux-gnu': machine `x86_64-pc' not recognized
-----

while it should do

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machine2 # /usr/share/gnuconfig/config.sub x86_64-pc-linux-gnu
x86_64-pc-linux-gnu
-----

Thank you.

Regards,
Martin