From e3ffbc53cb6a8d1151772ac081f1f2db1c7c9de4 Mon Sep 17 00:00:00 2001
From: Kornel Benko <kornel@lyx.org>
Date: Thu, 21 May 2020 16:09:21 +0200
Subject: [PATCH] Tools(listFontWithLang.pl): Prohibit inserting multiple
 entries of same command line option

---
 development/tools/GetOptions.pm | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/development/tools/GetOptions.pm b/development/tools/GetOptions.pm
index 5660b02925..193e570db9 100644
--- a/development/tools/GetOptions.pm
+++ b/development/tools/GetOptions.pm
@@ -75,6 +75,18 @@ sub handleOptions($)
   while( my( $option, $value, $pretty ) = Getopt::Mixed::nextOption()) {
     if (defined($optionsDef{$option})) {
       my $fieldname = $optionsDef{$option}->{fieldname};
+      if (exists($options{$fieldname})) {
+	print "Option $option already set\n";
+	print "Value \"$value\" would overwrite ";
+	if (ref($options{$fieldname}) eq "ARRAY") {
+	  print "\"" . join(',', @{$options{$fieldname}}) . "\"\n";
+	}
+	else {
+	  print "\"$options{$fieldname}\"\n";
+	}
+	$option = "h";
+	$fieldname = "help";
+      }
       if ($option eq "h") {
         print "Syntax: $0 options xxxx ...\n";
         print "Available options:\n";