I suspect you messed up your test.

Sorry, the absence of error message was simply because I also had a 'junk.bat' in the same directory that did nothing silently. But it doesn't invalidate the premise.

Having deleted that, here is a full re-test in a completely virgin session, that I believe confirms the source of this old 'mystery bug': 

Microsoft Windows [Version 6.0.6001]
Copyright (c) 2006 Microsoft Corporation.  All rights reserved.

c:\>cd test

c:\test>set pathext
PATHEXT=.pl;.COM;.EXE;.BAT;.CMD;

c:\test>junk junk.pl
'print "'$_'" while <>;
'
c:\test>junk < junk.pl
'print "'$_'" while <>;
'
c:\test>type junk.pl | junk
'print "'$_'" while <>;
'
c:\test>set pathext=.com;.exe;.bat;.cmd;

c:\test>set pathext
PATHEXT=.com;.exe;.bat;.cmd;

c:\test>junk junk.pl
'junk' is not recognized as an internal or external command,
operable program or batch file.

c:\test>junk < junk.pl
'junk' is not recognized as an internal or external command,
operable program or batch file.

c:\test>type junk.pl | junk
'junk' is not recognized as an internal or external command,
operable program or batch file.

c:\test>set pathexe=%pathext%.pl;

c:\test>set pathext
PATHEXT=.com;.exe;.bat;.cmd;

c:\test>set pathext=%pathext%.pl;

c:\test>set pathext
PATHEXT=.com;.exe;.bat;.cmd;.pl;

c:\test>junk junk.pl
'print "'$_'" while <>;
'
c:\test>junk < junk.pl
'print "'$_'" while <>;
'
c:\test>type junk.pl | junk
'print "'$_'" while <>;
'
c:\test>

[download]

In reply to Re^4: Out of date over <> and 5.10 (redir) by BrowserUk
in thread Out of date over <> and 5.10 by hsmyers

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