From 362cd6c6433b17a95fda879ad449a72613df64dc Mon Sep 17 00:00:00 2001
From: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Date: Fri, 14 Mar 2025 12:16:17 +0200
Subject: [PATCH 3/3] use better comment for the 0th 'reserved' entry in the
 maps

---
 .../unicode/generate-unicode_case_table.pl    | 33 +++++++++++--------
 src/include/common/unicode_case_table.h       | 10 +++---
 2 files changed, 24 insertions(+), 19 deletions(-)

diff --git a/src/common/unicode/generate-unicode_case_table.pl b/src/common/unicode/generate-unicode_case_table.pl
index 1d57cccc4d0..7765b7a5851 100644
--- a/src/common/unicode/generate-unicode_case_table.pl
+++ b/src/common/unicode/generate-unicode_case_table.pl
@@ -330,15 +330,15 @@ foreach my $code (sort { $a <=> $b } (keys %special))
 }
 print $OT "};\n";
 
-# Separate maps for each case form with initial empty map. The first
-# element is the result code point, and the second element is the
-# input code point (which is not ultimately stored in the C array,
-# it's just there as a comment).
-my @map_lower = ([ 0, 0 ]);
-my @map_title = ([ 0, 0 ]);
-my @map_upper = ([ 0, 0 ]);
-my @map_fold = ([ 0, 0 ]);
-my @map_special = ([ 0, 0 ]);
+# Separate maps for each case form, starting with the reserved entry
+# at index 0. The first element is the result code point, and the
+# second element is the input code point (which is not ultimately
+# stored in the C array, it's just there as a comment).
+my @map_lower = ([ 0, -1 ]);
+my @map_title = ([ 0, -1 ]);
+my @map_upper = ([ 0, -1 ]);
+my @map_fold = ([ 0, -1 ]);
+my @map_special = ([ 0, -1 ]);
 
 # Current index into the map arrays above.
 my $index = 1;
@@ -428,8 +428,9 @@ EOS
 
 foreach my $entry (@map_lower)
 {
+	my $comment = @$entry[1] == -1 ? "reserved" : sprintf("U+%06x", @$entry[1]);
 	print $OT
-	  sprintf("\t0x%06x,\t\t\t\t\t/* U+%06x */\n", @$entry[0], @$entry[1]);
+	  sprintf("\t0x%06x,\t\t\t\t\t/* %s */\n", @$entry[0], $comment);
 }
 
 print $OT "\n};\n";
@@ -442,8 +443,9 @@ EOS
 
 foreach my $entry (@map_title)
 {
+	my $comment = @$entry[1] == -1 ? "reserved" : sprintf("U+%06x", @$entry[1]);
 	print $OT
-	  sprintf("\t0x%06x,\t\t\t\t\t/* U+%06x */\n", @$entry[0], @$entry[1]);
+	  sprintf("\t0x%06x,\t\t\t\t\t/* %s */\n", @$entry[0], $comment);
 }
 
 print $OT "\n};\n";
@@ -456,8 +458,9 @@ EOS
 
 foreach my $entry (@map_upper)
 {
+	my $comment = @$entry[1] == -1 ? "reserved" : sprintf("U+%06x", @$entry[1]);
 	print $OT
-	  sprintf("\t0x%06x,\t\t\t\t\t/* U+%06x */\n", @$entry[0], @$entry[1]);
+	  sprintf("\t0x%06x,\t\t\t\t\t/* %s */\n", @$entry[0], $comment);
 }
 
 print $OT "\n};\n";
@@ -470,8 +473,9 @@ EOS
 
 foreach my $entry (@map_fold)
 {
+	my $comment = @$entry[1] == -1 ? "reserved" : sprintf("U+%06x", @$entry[1]);
 	print $OT
-	  sprintf("\t0x%06x,\t\t\t\t\t/* U+%06x */\n", @$entry[0], @$entry[1]);
+	  sprintf("\t0x%06x,\t\t\t\t\t/* %s */\n", @$entry[0], $comment);
 }
 
 print $OT "\n};\n";
@@ -484,8 +488,9 @@ EOS
 
 foreach my $entry (@map_special)
 {
+	my $comment = @$entry[1] == -1 ? "reserved" : sprintf("U+%06x", @$entry[1]);
 	print $OT
-	  sprintf("\t%d,\t\t\t\t\t/* U+%06x */\n", @$entry[0], @$entry[1]);
+	  sprintf("\t%d,\t\t\t\t\t/* %s */\n", @$entry[0], $comment);
 }
 
 print $OT "\n};\n";
diff --git a/src/include/common/unicode_case_table.h b/src/include/common/unicode_case_table.h
index bbc4687d9a0..f8a10b84eea 100644
--- a/src/include/common/unicode_case_table.h
+++ b/src/include/common/unicode_case_table.h
@@ -164,7 +164,7 @@ static const pg_special_case special_case[106] =
 
 static const pg_wchar case_map_lower[1677] =
 {
-	0x000000,					/* U+000000 */
+	0x000000,					/* reserved */
 	0x000000,					/* U+000000 */
 	0x000001,					/* U+000001 */
 	0x000002,					/* U+000002 */
@@ -1846,7 +1846,7 @@ static const pg_wchar case_map_lower[1677] =
 
 static const pg_wchar case_map_title[1677] =
 {
-	0x000000,					/* U+000000 */
+	0x000000,					/* reserved */
 	0x000000,					/* U+000000 */
 	0x000001,					/* U+000001 */
 	0x000002,					/* U+000002 */
@@ -3528,7 +3528,7 @@ static const pg_wchar case_map_title[1677] =
 
 static const pg_wchar case_map_upper[1677] =
 {
-	0x000000,					/* U+000000 */
+	0x000000,					/* reserved */
 	0x000000,					/* U+000000 */
 	0x000001,					/* U+000001 */
 	0x000002,					/* U+000002 */
@@ -5210,7 +5210,7 @@ static const pg_wchar case_map_upper[1677] =
 
 static const pg_wchar case_map_fold[1677] =
 {
-	0x000000,					/* U+000000 */
+	0x000000,					/* reserved */
 	0x000000,					/* U+000000 */
 	0x000001,					/* U+000001 */
 	0x000002,					/* U+000002 */
@@ -6892,7 +6892,7 @@ static const pg_wchar case_map_fold[1677] =
 
 static const uint8 case_map_special[1677] =
 {
-	0,					/* U+000000 */
+	0,					/* reserved */
 	0,					/* U+000000 */
 	0,					/* U+000001 */
 	0,					/* U+000002 */
-- 
2.39.5