check-gdbug.php

<?php
    ob_start();
    
if (isset($argv)) {
    $env = "CLI";
} else {
    $env = "WEB";
}
    
    print wordwrap("Some version of the GD graphics library have a bug in their handling of Alpha channels. Unfortunately, Weathermap uses these to draw Nodes.");
    print ($env=='CLI'?"\n\n":"\n<p>");
    
    print wordwrap("This program will test if your PHP installation is using a buggy GD library.");
    print ($env=='CLI'?"\n\n":"\n<p>");
    
    print wordwrap("If you are, you should either use PHP's built-in (aka 'bundled') GD library, or update to GD Version 2.0.34 or newer. Weathermap REQUIRES working Alpha support.");
    print ($env=='CLI'?"\n\n":"\n<p>");
    
    print wordwrap("Let's see if you have the GD transparency bug...");
    print ($env=='CLI'?"\n\n":"\n<p>");
    print wordwrap("If you see no more output, or a segfault, then you do, and you'll need to upgrade.");
    print ($env=='CLI'?"\n\n":"\n<p>");
    print wordwrap("If you get other errors, like 'undefined function', then run check.php to\nmake sure that your PHP installation is otherwise OK.");
             print ($env=='CLI'?"\n\n":"\n<p>");
    print "Here we go...";
    print ($env=='CLI'?"\n\n":"\n<p>");
    
    // make sure even the affected folks can see the explanation
    ob_flush();
    flush();
    
    $temp_width = 10;
    $temp_height = 10;
    
    $node_im=imagecreatetruecolor($temp_width, $temp_height);
    imageSaveAlpha($node_im, true);
    $nothing=imagecolorallocatealpha($node_im, 128, 0, 0, 127);
    imagefill($node_im, 0, 0, $nothing);
    imagedestroy($node_im);
    
    print "...nope. We got past the risky part, so that's good.\nYour GD library looks healthy.\n";
    print ($env=='CLI'?"\n":"\n<p>");