diff --git a/tools/make_unicode b/tools/make_unicode
index 1c81a7e82ce..27d23bffb0e 100755
--- a/tools/make_unicode
+++ b/tools/make_unicode
@@ -351,8 +351,8 @@ my @tolower_table = ();
 my @toupper_table = ();
 my @digitmap_table = ();
 my @compatmap_table = ();
-my @category_table = (0) x 65536;
-my @joining_table = (0) x 65536;
+my @category_table = ();
+my @joining_table = ();
 my @direction_table = ();
 my @decomp_table = ();
 my @compose_table = ();
@@ -1176,7 +1176,7 @@ sub get_lb_ranges()
 sub dump_indic($)
 {
     my $filename = shift;
-    my @indic_table = ($indic_types{'Other'}) x 65536;
+    my @indic_table;
 
     my $INPUT = open_data_file( $UNIDATA, "IndicSyllabicCategory.txt" );
     while (<$INPUT>)
@@ -1245,7 +1245,7 @@ sub dump_indic($)
     print OUTPUT "/*       and from $UNIDATA/IndicPositionalCategory.txt */\n";
     print OUTPUT "/* DO NOT EDIT!! */\n\n";
 
-    dump_two_level_mapping( "indic_syllabic_table", @indic_table);
+    dump_two_level_mapping( "indic_syllabic_table", $indic_types{'Other'}, @indic_table );
 
     close OUTPUT;
     save_file($filename);
@@ -1256,7 +1256,7 @@ sub dump_indic($)
 sub dump_linebreak($)
 {
     my $filename = shift;
-    my @break_table = ($break_types{'XX'}) x 65536;
+    my @break_table;
     my $next_group = 0;
 
     my $INPUT = open_data_file( $UNIDATA, "LineBreak.txt" );
@@ -1292,7 +1292,7 @@ sub dump_linebreak($)
     print OUTPUT "/* generated from $UNIDATA/LineBreak.txt */\n";
     print OUTPUT "/* DO NOT EDIT!! */\n\n";
 
-    dump_two_level_mapping( "wine_linebreak_table", @break_table);
+    dump_two_level_mapping( "wine_linebreak_table", $break_types{'XX'}, @break_table );
 
     close OUTPUT;
     save_file($filename);
@@ -1304,7 +1304,7 @@ sub dump_scripts($)
 {
     my $filename = shift;
     my $header = $filename;
-    my @scripts_table = (0) x 65536; # 0 means unknown script
+    my @scripts_table;
     my $script_index;
     my %scripts;
     my $i;
@@ -1406,7 +1406,7 @@ sub dump_scripts($)
     print OUTPUT "/* generated from $UNIDATA/Scripts.txt */\n";
     print OUTPUT "/* DO NOT EDIT!! */\n\n";
 
-    dump_two_level_mapping( "wine_scripts_table", @scripts_table);
+    dump_two_level_mapping( "wine_scripts_table", 0, @scripts_table );
     close OUTPUT;
     save_file($filename);
 }
@@ -1449,7 +1449,7 @@ sub dump_mirroring($)
 sub dump_bracket($)
 {
     my $filename = shift;
-    my @bracket_table = (0) x 65536;
+    my @bracket_table;
 
     my $INPUT = open_data_file( $UNIDATA, "BidiBrackets.txt" );
     while (<$INPUT>)
@@ -1476,7 +1476,7 @@ sub dump_bracket($)
     print OUTPUT "/* generated from $UNIDATA/BidiBrackets.txt */\n";
     print OUTPUT "/* DO NOT EDIT!! */\n\n";
 
-    dump_two_level_mapping( "bidi_bracket_table", @bracket_table);
+    dump_two_level_mapping( "bidi_bracket_table", 0, @bracket_table );
 
     close OUTPUT;
     save_file($filename);
@@ -1516,7 +1516,7 @@ sub dump_shaping($)
     print OUTPUT "/* generated from $UNIDATA/ArabicShaping.txt */\n";
     print OUTPUT "/* DO NOT EDIT!! */\n\n";
 
-    dump_two_level_mapping( "wine_shaping_table", @joining_table );
+    dump_two_level_mapping( "wine_shaping_table", 0, @joining_table );
 
     print OUTPUT "\nconst unsigned short wine_shaping_forms[256][4] =\n{\n";
     for (my $i = 0x600; $i <= 0x6ff; $i++)
@@ -1538,7 +1538,7 @@ sub dump_shaping($)
 sub dump_vertical($)
 {
     my $filename = shift;
-    my @vertical_table = ($vertical_types{'R'}) x 65536;
+    my @vertical_table;
 
     my $INPUT = open_data_file( $VERTICALDATA, "VerticalOrientation-11.txt" );
     while (<$INPUT>)
@@ -1576,7 +1576,7 @@ sub dump_vertical($)
     print OUTPUT "/* generated from $VERTICALDATA/VerticalOrientation-11.txt */\n";
     print OUTPUT "/* DO NOT EDIT!! */\n\n";
 
-    dump_two_level_mapping( "vertical_orientation_table", @vertical_table);
+    dump_two_level_mapping( "vertical_orientation_table", $vertical_types{'R'}, @vertical_table );
 
     close OUTPUT;
     save_file($filename);
@@ -1672,9 +1672,10 @@ sub DUMP_CASE_TABLE($@)
 
 ################################################################
 # compress a mapping table by removing identical rows
-sub compress_array($@)
+sub compress_array($$@)
 {
     my $rows = shift;
+    my $def = shift;
     my @table = @_;
     my $len = @table / $rows;
     my @array = (0) x $rows;
@@ -1683,7 +1684,8 @@ sub compress_array($@)
     # try to merge table rows
     for (my $row = 0; $row < $rows; $row++)
     {
-        my $rowtxt = pack "S*", @table[($row * $len)..($row * $len + $len - 1)];
+        my @table_row = map { defined($_) ? $_ : $def; } @table[($row * $len)..($row * $len + $len - 1)];
+        my $rowtxt = pack "S*", @table_row;
         if (defined($sequences{$rowtxt}))
         {
             # reuse an existing row
@@ -1693,7 +1695,7 @@ sub compress_array($@)
         {
             # create a new row
             $sequences{$rowtxt} = $array[$row] = $#array + 1;
-            push @array, @table[$row * $len..$row * $len + $len - 1];
+            push @array, @table_row;
         }
     }
     return @array;
@@ -1701,10 +1703,11 @@ sub compress_array($@)
 
 ################################################################
 # dump a simple char -> 16-bit value mapping table
-sub dump_simple_mapping($@)
+sub dump_simple_mapping($$@)
 {
     my $name = shift;
-    my @array = compress_array( 256, @_[0..65535] );
+    my $def = shift;
+    my @array = compress_array( 256, $def, @_[0..65535] );
 
     printf OUTPUT "const unsigned short %s[%d] =\n{\n", $name, $#array+1;
     printf OUTPUT "    /* offsets */\n%s,\n", DUMP_ARRAY( "0x%04x", 0, @array[0..255] );
@@ -1713,11 +1716,12 @@ sub dump_simple_mapping($@)
 
 ################################################################
 # dump a char -> 16-bit value mapping table using two-level tables
-sub dump_two_level_mapping($@)
+sub dump_two_level_mapping($$@)
 {
     my $name = shift;
-    my @row_array = compress_array( 4096, @_[0..65535] );
-    my @array = compress_array( 256, @row_array[0..4095] );
+    my $def = shift;
+    my @row_array = compress_array( 4096, $def, @_[0..65535] );
+    my @array = compress_array( 256, 0, @row_array[0..4095] );
 
     for (my $i = 256; $i < @array; $i++) { $array[$i] += @array - 4096; }
 
@@ -1880,7 +1884,7 @@ sub dump_nameprep($)
 {
     my $filename = shift;
     my @mapping_table = ();
-    my @flags_table = (0) x 65536;
+    my @flags_table;
 
     my $INPUT = open_data_file( $RFCS, $STRINGPREP );
     while (<$INPUT>)
@@ -1911,7 +1915,7 @@ sub dump_nameprep($)
     print OUTPUT "/* generated from $RFCS/$STRINGPREP */\n";
     print OUTPUT "/* DO NOT EDIT!! */\n\n";
 
-    dump_two_level_mapping( "nameprep_char_type", @flags_table );
+    dump_two_level_mapping( "nameprep_char_type", 0, @flags_table );
 
     ######### mapping table
     # first determine all the 16-char subsets that contain something
@@ -2006,7 +2010,7 @@ sub DUMP_CTYPE_TABLES($)
         $category_table[$i] |= $direction_table[$i] << 12 if defined $direction_table[$i];
     }
 
-    dump_simple_mapping( "wine_wctype_table", @category_table );
+    dump_simple_mapping( "wine_wctype_table", 0, @category_table );
 
     close OUTPUT;
     save_file($filename);