Description:
------------
---
From manual page: https://php.net/function.imagefilltoborder
---
当被填充的图形是由imagefilledellipse创建时,可能出现无法正确填充的情况

Test script:
---------------
<?php
header("content-type:image/png");
$res=imagecreate(800,400);
$bmgColor=imagecolorallocate($res,54,125,215);
$darkPen1=imagecolorallocate($res,255*0.5,69*0.5,215*0.5);
$penColor1=imagecolorallocate($res,255,69,215);

$filledTime=15;
while($filledTime--)
{
    imagefilledellipse($res,400,200+$filledTime,100,40,$darkPen1); 
}   
imagefilledellipse($res,400,200,100,40,$penColor1);   
      
//问题出现在这里,这时第三个参数为200
imagefilltoborder($res,400,200,$bmgColor,$penColor1); 

imagepng($res);
imagedestroy($res);
?>

Expected result:
----------------
<?php
header("content-type:image/png");
$res=imagecreate(800,400);
$bmgColor=imagecolorallocate($res,54,125,215);
$darkPen1=imagecolorallocate($res,255*0.5,69*0.5,215*0.5);
$penColor1=imagecolorallocate($res,255,69,215);

$filledTime=15;
while($filledTime--)
{
    imagefilledellipse($res,400,200+$filledTime,100,40,$darkPen1); 
}   
imagefilledellipse($res,400,200,100,40,$penColor1);  
       
/*当第三个参数改为202时,这才是预期的结果。但是第三个参数为200与202时不应该出现不同的结果，因为(400,200)与(400,202)它们都是在由imagefilledellipse($res,400,200,100,40,$penColor1)语句创建的区域里*/
imagefilltoborder($res,400,202,$bmgColor,$penColor1); 

imagepng($res);
imagedestroy($res);
?>