Bash 5.2: broken built-in printf for float numbers

[Thomas Dreibholz]

Hi,

Bash 5.2 has a broken built-in printf for float numbers.

Example: printf "%5.1f" 1024 should print "1024.0" (with standard locale 
LC_ALL=C.UTF-8)

Testing the Bash shell in different versions of recent Debian and Ubuntu 
setups, the output is wrong. Bug tracker for Debian: 
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1081424 .Depending on 
the Debian/Ubuntu patch version of Bash, the output made by Bash is 
either complete garbage (random), or "nan" or "-0.0". The output of the 
external command /usr/bin/printf is always correct.

The attached small Bash script runs Docker with different Debian and 
Ubuntu containers, generating test output with version information. The 
generated output of ./bash-bug-test1 | tee bash-bug-test1.log is 
attached as well.

--
Best regards / Mit freundlichen Grüßen / Med vennlig hilsen

=======================================================================
 Thomas Dreibholz

 Simula@OsloMet -- Simula Metropolitan Centre for Digital Engineering
 Centre for Resilient Networks and Applications
 Pilestredet 52
 0167 Oslo, Norway
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 E-Mail:     dreibh@simula.no
 Homepage:   http://simula.no/people/dreibh
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bash-bug-test1.log
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bash-bug-test1
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