From 01a8eaa3db2c015b25c0cf53df96b12493f3db58 Mon Sep 17 00:00:00 2001
From: "Steinar H. Gunderson" <sgunderson@bigfoot.com>
Date: Sat, 6 Jan 2018 13:00:26 +0100
Subject: [PATCH 1/1] Support starting from a nonstandard position.

---
 Position.pm          |  3 +++
 remoteglot.pl        | 18 ++++++++++++++++--
 www/js/remoteglot.js | 10 ++++++----
 3 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/Position.pm b/Position.pm
index 39b89ac..6976c96 100644
--- a/Position.pm
+++ b/Position.pm
@@ -218,6 +218,9 @@ sub make_move {
 	}
 	$np->{'player_w'} = $pos->{'player_w'};
 	$np->{'player_b'} = $pos->{'player_b'};
+	if (exists($pos->{'start_fen'})) {
+		$np->{'start_fen'} = $pos->{'start_fen'};
+	}
 	if (defined($pretty_move)) {
 		$np->{'last_move'} = $pretty_move;
 	} else {
diff --git a/remoteglot.pl b/remoteglot.pl
index 19f0446..7f4fd3c 100755
--- a/remoteglot.pl
+++ b/remoteglot.pl
@@ -286,7 +286,16 @@ sub handle_pgn {
 			my $black = $pgn->black;
 			$white =~ s/,.*//;  # Remove first name.
 			$black =~ s/,.*//;  # Remove first name.
-			my $pos = Position->start_pos($white, $black);
+			my $tags = $pgn->tags();
+			my $pos;
+			if (exists($tags->{'FEN'})) {
+				$pos = Position->from_fen($tags->{'FEN'});
+				$pos->{'player_w'} = $white;
+				$pos->{'player_b'} = $black;
+				$pos->{'start_fen'} = $tags->{'FEN'};
+			} else {
+				$pos = Position->start_pos($white, $black);
+			}
 			my $moves = $pgn->moves;
 			my @uci_moves = ();
 			my @repretty_moves = ();
@@ -880,7 +889,12 @@ sub output_json {
 
 		local $dbh->{AutoCommit} = 0;
 		my $q = $dbh->prepare('SELECT * FROM scores WHERE id=?');
-		my $pos = Position->start_pos('white', 'black');
+		my $pos;
+		if (exists($pos_calculating->{'start_fen'})) {
+			$pos = Position->from_fen($pos_calculating->{'start_fen'});
+		} else {
+			$pos = Position->start_pos('white', 'black');
+		}
 		my $halfmove_num = 0;
 		for my $move (@{$pos_calculating->{'history'}}) {
 			my $id = id_for_pos($pos, $halfmove_num);
diff --git a/www/js/remoteglot.js b/www/js/remoteglot.js
index d614c7e..ff566ab 100644
--- a/www/js/remoteglot.js
+++ b/www/js/remoteglot.js
@@ -864,7 +864,7 @@ var update_refutation_lines = function() {
  */
 var chess_from = function(fen, moves, last_move) {
 	var hiddenboard = new Chess();
-	if (fen !== null) {
+	if (fen !== null && fen !== undefined) {
 		hiddenboard.load(fen);
 	}
 	for (var i = 0; i <= last_move; ++i) {
@@ -957,7 +957,8 @@ var update_board = function() {
 	// unconditionally taken from current_data (we're not interested in
 	// historic history).
 	if (current_data['position']['history']) {
-		add_pv('start', current_data['position']['history'], 1, 'W', null, 0, 8, true);
+		var start = (current_data['position'] && current_data['position']['start_fen']) ? current_data['position']['start_fen'] : 'start';
+		add_pv(start, current_data['position']['history'], 1, 'W', null, 0, 8, true);
 	} else {
 		display_lines.push(null);
 	}
@@ -1083,7 +1084,8 @@ var update_board = function() {
 		// We don't have historic analysis for this position, but we
 		// can reconstruct what the last move was by just replaying
 		// from the start.
-		var hiddenboard = chess_from(null, current_display_line.pv, current_display_move);
+		var position = (data['position'] && data['position']['start_fen']) ? data['position']['start_fen'] : null;
+		var hiddenboard = chess_from(position, current_display_line.pv, current_display_move);
 		var moves = hiddenboard.history({ verbose: true });
 		last_move = moves.pop();
 		highlight_from = last_move.from;
@@ -1607,7 +1609,7 @@ var update_historic_analysis = function() {
 	}
 
 	// Fetch old analysis for this line if it exists.
-	var hiddenboard = chess_from(null, current_display_line.pv, current_display_move);
+	var hiddenboard = chess_from(current_display_line.start_fen, current_display_line.pv, current_display_move);
 	var filename = "/history/move" + (current_display_move + 1) + "-" +
 		hiddenboard.fen().replace(/ /g, '_').replace(/\//g, '-') + ".json";
 
-- 
2.39.2