Document config_args limitations reported in [perl #70912]

diff --git a/U/mkglossary b/U/mkglossary
index abafdb3..f590ac3 100755 (executable)
--- a/U/mkglossary
+++ b/U/mkglossary
@@ -80,6 +80,7 @@ close $fh or die "$0: close $Loc: $!";
 for (@WANTED) {
     chomp;
     m/^#/ and next;    # Skip comments
+    m/^:/ and next;    # Skip comments
     m/^$/ and next;    # Skip empty sections
     my ($var, $val) = split /=/, $_, 2;
 
@@ -118,6 +119,8 @@ EOE
     # with capital letters, metalint considers them to be "special
     # unit" symbols.  It's easier to define them here than to try
     # to fool metalint any further.   --AD  22 Oct 1999
+    # Similarly, handle the config_arg* variables from Options.U.
+    # -- AD 8 Dec 2009
     if (exists $predef{$var}) {
        print  $predef{$var};
        next;
@@ -179,3 +182,20 @@ PERL_PATCHLEVEL (Oldsyms.U):
        come from the .patch file, which is available when the perl
        source tree was fetched with rsync.
 
+config_args (Options.U):
+       This variable contains a single string giving the command-line
+       arguments passed to Configure.  Spaces within arguments,
+       quotes, and escaped characters are not correctly preserved.
+       To reconstruct the command line, you must assemble the individual
+       command line pieces, given in config_arg[0-9]*.
+
+config_arg0 (Options.U):
+       This variable contains the string used to invoke the Configure
+       command, as reported by the shell in the $0 variable.
+
+config_argc (Options.U):
+       This variable countains the number of command-line arguments
+       passed to Configure, as reported by the shell in the $# variable.
+       The individual arguments are stored as variables config_argc1,
+       config_argc2, etc.
+