charnames: Deprecate character names with spacing issues

A user-defined character name with trailing or multiple spaces in a row
is likely a typo, and hence likely won't match what the other uses of
it.  These names also won't work if we extend :loose to these.  This
now generates a warning.

1 files changed, 16 insertions, 0 deletions

diff --git a/pod/perldiag.pod b/pod/perldiag.pod
index 79afa88ba9..9e6ee34ece 100644
--- a/pod/perldiag.pod
+++ b/pod/perldiag.pod
@@ -219,6 +219,14 @@ result of the value of the environment variable PERLIO.
 (D deprecated) Really old Perl let you omit the @ on array names in some
 spots.  This is now heavily deprecated.
 
+=item A sequence of multiple spaces in a charnames alias definition is deprecated
+
+(D) You defined a character name which had multiple space characters in
+a row.  Change them to single spaces.  Usually these names are defined
+in the C<:alias> import argument to C<use charnames>, but they could be
+defined by a translator installed into C<$^H{charnames}>.  See
+L<charnames/CUSTOM ALIASES>.
+
 =item assertion botched: %s
 
 (X) The malloc package that comes with Perl had an internal failure.
@@ -4956,6 +4964,14 @@ Check the #! line, or manually feed your script into Perl yourself.
 (F) The regular expression ends with an unbackslashed backslash.
 Backslash it.   See L<perlre>.
 
+=item Trailing white-space in a charnames alias definition is deprecated
+
+(D) You defined a character name which ended in a space character.
+Remove the trailing space(s).  Usually these names are defined in the
+C<:alias> import argument to C<use charnames>, but they could be defined
+by a translator installed into C<$^H{charnames}>.
+See L<charnames/CUSTOM ALIASES>.
+
 =item Transliteration pattern not terminated
 
 (F) The lexer couldn't find the interior delimiter of a tr/// or tr[][]