Fix #53156: imagerectangle problem with point ordering

ext/gd/libgd/gd.c

@@ -2044,7 +2044,9 @@ void gdImageRectangle (gdImagePtr im, int x1, int y1, int x2, int y2, int color)
 		t=y1;
 		y1 = y2;
 		y2 = t;
-
+	}
+
+	if (x2 < x1) {
 		t = x1;
 		x1 = x2;
 		x2 = t;

ext/gd/tests/bug53156.phpt

@@ -0,0 +1,57 @@
+--TEST--
+Bug #53156 (imagerectangle problem with point ordering)
+--SKIPIF--
+<?php
+if (!extension_loaded('gd')) die('skip gd extension not available');
+?>
+--FILE--
+<?php
+function draw_and_check_pixel($x, $y)
+{
+    global $img, $black, $red;
+
+    echo (imagecolorat($img, $x, $y) === $black) ? '+' : '-';
+    imagesetpixel($img, $x, $y, $red);
+}
+
+function draw_and_check_rectangle($x1, $y1, $x2, $y2)
+{
+    global $img, $black;
+
+    echo 'Rectangle: ';
+    imagerectangle($img, $x1, $y1, $x2, $y2, $black);
+    $x = ($x1 + $x2) / 2;
+    $y = ($y1 + $y2) / 2;
+    draw_and_check_pixel($x,  $y1);
+    draw_and_check_pixel($x1, $y);
+    draw_and_check_pixel($x,  $y2);
+    draw_and_check_pixel($x2, $y);
+    echo PHP_EOL;
+}
+
+$img = imagecreate(110, 210);
+$bgnd  = imagecolorallocate($img, 255, 255, 255);
+$black = imagecolorallocate($img,   0,   0,   0);
+$red   = imagecolorallocate($img, 255,   0,   0);
+
+draw_and_check_rectangle( 10,  10,  50,  50);
+draw_and_check_rectangle( 50,  60,  10, 100);
+draw_and_check_rectangle( 50, 150,  10, 110);
+draw_and_check_rectangle( 10, 200,  50, 160);
+imagesetthickness($img, 4);
+draw_and_check_rectangle( 60,  10, 100,  50);
+draw_and_check_rectangle(100,  60,  60, 100);
+draw_and_check_rectangle(100, 150,  60, 110);
+draw_and_check_rectangle( 60, 200, 100, 160);
+
+//imagepng($img, __DIR__ . '/bug53156.png'); // debug
+?>
+--EXPECT--
+Rectangle: ++++
+Rectangle: ++++
+Rectangle: ++++
+Rectangle: ++++
+Rectangle: ++++
+Rectangle: ++++
+Rectangle: ++++
+Rectangle: ++++