A picture is worth a thousand message digests

The bundled GD test suites makes heavy use of md5() to verify the result
of drawing operations. This leads to fragile tests (even a slight change
in a PNG header would cause failure, and of course there is the
possibility of collisions), and even worse, eventual test failures are
rather unrevealing.

Therefore we replace all md5() verification with a simplistic
test_image_equals_file(), which is basically a simplified port of libgd's
gdTestImageCompareToFile(), adapted to the needs of PHPTs.

In the long run better tests helpers should be introduced (see also
<http://news.php.net/php.internals/94081>), but for now this solution
is preferable over the former.

(cherry picked from commit 24f9e96792)

.gitignore

@@ -135,6 +135,7 @@ tests/*/*.sh
 */tests/*/*.sh
 */*/tests/*.diff
 */*/tests/*.out
+*/*/tests/*.out.png
 */*/tests/*.php
 */*/tests/*.exp
 */*/tests/*.log

ext/gd/tests/bug22544.phpt

@@ -8,16 +8,13 @@ Bug #22544 (TrueColor transparency in PNG images).
 ?>
 --FILE--
 <?php
-	$dest = dirname(realpath(__FILE__)) . '/bug22544.png';
-	@unlink($dest);
 	$image = imageCreateTruecolor(640, 100);
 	$transparent = imageColorAllocate($image, 0, 0, 0);
 	$red = imageColorAllocate($image, 255, 50, 50);
 	imageColorTransparent($image, $transparent);
 	imageFilledRectangle($image, 0, 0, 640-1, 100-1, $transparent);
-	imagegd($image, $dest);
-	echo md5_file($dest) . "\n";
-	@unlink($dest);
+	include_once __DIR__ . '/func.inc';
+	test_image_equals_file(__DIR__ . '/bug22544.png', $image);
 ?>
 --EXPECT--
-7643ef115f642a79c2de6e411f485ddd
+The images are equal.

ext/gd/tests/bug43828.phpt

@@ -17,10 +17,10 @@ imagefilledrectangle($im, 0,0, 99,99, $transparent);
 $color = imagecolorallocatealpha($im, 0, 255, 0, 100);
 imagefilledarc($im, 49, 49, 99,99, 0 , 360, $color, IMG_ARC_PIE);
 
-ob_start();
-imagegd($im);
-echo md5(ob_get_clean());
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/bug43828.png', $im);
+
 imagedestroy($im);
 ?>
 --EXPECT--
-2400a58cd7570b5472c25264715321cd
+The images are equal.

ext/gd/tests/bug66005.phpt

@@ -25,11 +25,10 @@ imagecopy($dest, $png_palette, 0, 0, 0, 0, 50, 50);
 imagecopy($dest, $png_24, 50, 0, 0, 0, 50, 50);
 imagecopy($dest, $png_full, 100, 0, 0, 0, 50, 50);
 
-ob_start();
-imagegd($dest);
-echo md5(ob_get_clean()), PHP_EOL;
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/bug66005.png', $dest);
 ?>
 ==DONE==
 --EXPECT--
-9b36049de01006b367efd433f1689043
+The images are equal.
 ==DONE==

ext/gd/tests/bug72604.phpt

@@ -10,10 +10,9 @@ if (!(imagetypes() & IMG_PNG)) die('skip requires PNG support');
 $im = imagecreatetruecolor(100, 100);
 imagesetthickness($im, 5);
 imagearc($im, 50, 50, 90, 90, 0, 360, 0xffffff);
-ob_start();
-imagegd($im);
-$imagestring = ob_get_clean();
-echo md5($imagestring);
+
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/bug72604.png', $im);
 ?>
 --EXPECT--
-4f5080080a774efe4fc8d55cd4a5849c
+The images are equal.

ext/gd/tests/bug72913.phpt

@@ -19,11 +19,10 @@ imagesavealpha($dst, true);
 
 imagecopy($dst, $src, 0,0, 0,0, 50,50);
 
-ob_start();
-imagegd($dst);
-echo md5(ob_get_clean()), PHP_EOL;
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/bug72913.png', $dst);
 ?>
 ==DONE==
 --EXPECT--
-f03c27f20710e21debd7090c660f1a1e
+The images are equal.
 ==DONE==

ext/gd/tests/func.inc

@@ -59,3 +59,71 @@ function get_libxpm_version()
 	return $version;
 }
 
+/**
+ * Tests that an in-memory image equals a PNG file.
+ *
+ * It checks for equal image sizes, and whether any pixels are different.
+ * The textual result is printed, so the EXPECT section should contain the line
+ * "The images are equal."
+ *
+ * If the PNG file does not exists, or the images are not equal, a diagnostic
+ * message is printed, and the actual file is stored right beside the temporary
+ * .php test file with the extension .out.png, to be able to manually inspect
+ * the result.
+ *
+ * @param string $filename
+ * @param resource $actual
+ * @return void
+ */
+function test_image_equals_file($filename, $actual)
+{
+	if (!file_exists($filename)) {
+		echo "The expected image does not exist.\n";
+		save_actual_image($actual);
+		return;
+	}
+	$expected = imagecreatefrompng($filename);
+	$exp_x = imagesx($expected);
+	$exp_y = imagesy($expected);
+	$act_x = imagesx($actual);
+	$act_y = imagesy($actual);
+	if ($exp_x != $act_x || $exp_y != $act_y) {
+		echo "The image size differs: expected {$exp_x}x{$exp_y}, got {$act_x}x{$act_y}.\n";
+		save_actual_image($actual);
+		imagedestroy($expected);
+		return;
+	}
+	$pixels_changed = 0;
+	for ($y = 0; $y < $exp_y; $y++) {
+		for ($x = 0; $x < $exp_x; $x ++) {
+			$exp_c = imagecolorat($expected, $x, $y);
+			$act_c = imagecolorat($actual, $x, $y);
+			if ($exp_c != $act_c) {
+				$pixels_changed++;
+			}
+		}
+	}
+	if (!$pixels_changed) {
+		echo "The images are equal.\n";
+	} else {
+		echo "The images differ in {$pixels_changed} pixels.\n";
+		save_actual_image($actual);
+	}
+	imagedestroy($expected);
+}
+
+/**
+ * Saves an actual image to disk.
+ *
+ * The image is saved right beside the temporary .php test file with the
+ * extension .out.png.
+ *
+ * @param resource $image
+ * @return void
+ */
+function save_actual_image($image)
+{
+	$pathinfo = pathinfo($_SERVER['SCRIPT_FILENAME']);
+	$filename = "{$pathinfo['dirname']}/{$pathinfo['filename']}.out.png";
+	imagepng($image, $filename);
+}

ext/gd/tests/imagearc_basic.phpt

@@ -17,12 +17,8 @@ $white = imagecolorallocate($image, 0xFF, 0xFF, 0xFF);
 //create an arc with white color    
 imagearc($image, 50, 50, 30, 30, 0, 180, $white);
 
-ob_start();
-imagegd($image);
-$img = ob_get_contents();
-ob_end_clean();
-
-echo md5(base64_encode($img));
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/imagearc_basic.png', $image);
 ?>
 --EXPECT--
-13149c3fd54a92a0d43cd5083a19b1d7
+The images are equal.

ext/gd/tests/imagearc_error1.phpt

@@ -17,13 +17,9 @@ $white = imagecolorallocate($image, 0xFF, 0xFF, 0xFF);
 //create an arc with white color    
 imagearc($image, 50, 50, 30, 30, 0, 180);
 
-ob_start();
-imagegd($image);
-$img = ob_get_contents();
-ob_end_clean();
-
-echo md5(base64_encode($img));
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/imagearc_error1.png', $image);
 ?>
 --EXPECTF--
 Warning: imagearc() expects exactly 8 parameters, 7 given in %s on line %d
-c5b7013900f5466aebfc42499a7ec8ec
+The images are equal.

ext/gd/tests/imagearc_variation1.phpt

@@ -17,12 +17,8 @@ $white = imagecolorallocate($image, 0xFF, 0xFF, 0xFF);
 //create an arc with white color    
 imagearc($image, 50, 50, 30, 30, 0, -90, $white);
 
-ob_start();
-imagegd($image);
-$img = ob_get_contents();
-ob_end_clean();
-
-echo md5(base64_encode($img));
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/imagearc_variation1.png', $image);
 ?>
 --EXPECT--
-fe662ebe7488057c43e38c5de43b1727
+The images are equal.

ext/gd/tests/imagearc_variation2.phpt

@@ -17,12 +17,8 @@ $white = imagecolorallocate($image, 0xFF, 0xFF, 0xFF);
 //create an arc with white color    
 imagearc($image, 50, 50, 30, 30, -90, 0, $white);
 
-ob_start();
-imagegd($image);
-$img = ob_get_contents();
-ob_end_clean();
-
-echo md5(base64_encode($img));
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/imagearc_variation2.png', $image);
 ?>
 --EXPECT--
-8bd78aa775b5f29e7227eaeebaa84889
+The images are equal.

ext/gd/tests/imagechar_basic.phpt

@@ -14,12 +14,8 @@ $white = imagecolorallocate($image, 255,255,255);
 
 $result = imagechar($image, 1, 5, 5, 'C', $white);
 
-ob_start();
-imagegd($image);
-$img = ob_get_contents();
-ob_end_clean();
-
-echo md5(base64_encode($img));
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/imagechar_basic.png', $image);
 ?>
 --EXPECT--
-f0291252e7ac2fadda25e63287e6860c
+The images are equal.

ext/gd/tests/imagecharup_basic.phpt

@@ -14,12 +14,8 @@ $white = imagecolorallocate($image, 255,255,255);
 
 $result = imagecharup($image, 1, 5, 5, 'C', $white);
 
-ob_start();
-imagegd($image);
-$img = ob_get_contents();
-ob_end_clean();
-
-echo md5(base64_encode($img));
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/imagecharup_basic.png', $image);
 ?>
 --EXPECT--
-c65aad5d78f934dee2a844e7978eabd5
+The images are equal.

ext/gd/tests/imagecolorallocatealpha_basic.phpt

@@ -20,14 +20,10 @@ $corA = imagecolorallocatealpha($img, 50, 100, 255, 50);
 $half =  imagefilledarc ( $img, 75, 75, 70, 70, 0, 180, $cor, IMG_ARC_PIE );
 $half2 =  imagefilledarc ( $img, 75, 75, 70, 70, 180, 360, $corA, IMG_ARC_PIE );
 
-ob_start();
-imagegd($img);
-$imgsrc = ob_get_contents();
-ob_end_clean();
-
-var_dump(md5(base64_encode($imgsrc)));
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/imagecolorallocatealpha_basic.png', $img);
 var_dump($corA);
 ?>
 --EXPECT--
-string(32) "0981ef94ee2209a8dccb59aa8ad07e18"
+The images are equal.
 int(842163455)

ext/gd/tests/imagecolorset_basic.phpt

@@ -23,13 +23,9 @@ $bg = imagecolorat($im, 0, 0);
 // Set the backgrund to be blue
 imagecolorset($im, $bg, 0, 0, 255);
 
-// Get output and generate md5 hash
-ob_start();
-imagegd($im);
-$result_image = ob_get_contents();
-ob_end_clean();
-echo md5(base64_encode($result_image));
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/imagecolorset_basic.png', $im);
 imagedestroy($im);
 ?>
 --EXPECT--
-85e406abd0a975c97b3403cad5d078c9
+The images are equal.

ext/gd/tests/imageconvolution_basic.phpt

@@ -22,12 +22,8 @@ $gaussian = array(
 
 imageconvolution($image, $gaussian, 16, 0);
 
-ob_start();
-imagegd($image);
-$img = ob_get_contents();
-ob_end_clean();
-
-echo md5(base64_encode($img));
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/imageconvolution_basic.png', $image);
 ?>
 --EXPECT--
-20979b45f8772cdbd78262af4e332638
+The images are equal.

ext/gd/tests/imagecreatetruecolor_basic.phpt

@@ -11,12 +11,8 @@ Rafael Dohms <rdohms [at] gmail [dot] com>
 <?php
 $image = imagecreatetruecolor(180, 30);
 
-ob_start();
-imagegd($image);
-$img = ob_get_contents();
-ob_end_clean();
-
-echo md5(base64_encode($img));
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/imagecreatetruecolor_basic.png', $image);
 ?>
 --EXPECT--
-da884f488a851e0267a316ad232aee86
+The images are equal.

ext/gd/tests/imageellipse_basic.phpt

@@ -16,12 +16,8 @@ $image = imagecreatetruecolor(400, 300);
 // Draw a white ellipse
 imageellipse($image, 200, 150, 300, 200, 16777215);
 
-ob_start();
-imagegd($image);
-$img = ob_get_contents();
-ob_end_clean();
-
-echo md5(base64_encode($img));
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/imageellipse_basic.png', $image);
 ?>
 --EXPECT--
-49c1544b012c3460c74cd04f1332d4ad
+The images are equal.

ext/gd/tests/imagefilledarc_basic.phpt

@@ -20,12 +20,8 @@ $white = imagecolorallocate($image, 0xFF, 0xFF, 0xFF);
 //create an arc and fill it with white color    
 imagefilledarc($image, 50, 50, 30, 30, 0, 90, $white, IMG_ARC_PIE);
 
-ob_start();
-imagegd($image);
-$img = ob_get_contents();
-ob_end_clean();
-
-echo md5(base64_encode($img));
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/imagefilledarc_basic.png', $image);
 ?>
 --EXPECT--
-87637c60ac0ceea48dbcaa4d98319f90
+The images are equal.

ext/gd/tests/imagefilledarc_error1.phpt

@@ -17,13 +17,9 @@ $white = imagecolorallocate($image, 0xFF, 0xFF, 0xFF);
 //create an arc and fill it with white color    
 imagefilledarc($image, 50, 50, 30, 30, 0, 90, $white);
 
-ob_start();
-imagegd($image);
-$img = ob_get_contents();
-ob_end_clean();
-
-echo md5(base64_encode($img));
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/imagefilledarc_error1.png', $image);
 ?>
 --EXPECTF--
 Warning: imagefilledarc() expects exactly 9 parameters, 8 given in %s on line %d
-c5b7013900f5466aebfc42499a7ec8ec
+The images are equal.

ext/gd/tests/imagefilledarc_variation1.phpt

@@ -20,12 +20,8 @@ $white = imagecolorallocate($image, 0xFF, 0xFF, 0xFF);
 //create an arc and fill it with white color    
 imagefilledarc($image, 50, 50, 30, 30, 0, -25, $white, IMG_ARC_PIE);
 
-ob_start();
-imagegd($image);
-$img = ob_get_contents();
-ob_end_clean();
-
-echo md5(base64_encode($img));
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/imagefilledarc_variation1.png', $image);
 ?>
 --EXPECT--
-f25f589b5c5fa7deead7242652919bcf
+The images are equal.

ext/gd/tests/imagefilledarc_variation2.phpt

@@ -20,12 +20,8 @@ $white = imagecolorallocate($image, 0xFF, 0xFF, 0xFF);
 //create an arc and fill it with white color    
 imagefilledarc($image, 50, 50, 30, 30, -25, 25, $white, IMG_ARC_PIE);
 
-ob_start();
-imagegd($image);
-$img = ob_get_contents();
-ob_end_clean();
-
-echo md5(base64_encode($img));
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/imagefilledarc_variation2.png', $image);
 ?>
 --EXPECT--
-43c2973eb4872903eb6f5464c7965a93
+The images are equal.

ext/gd/tests/imagefilledellipse_basic.phpt

@@ -14,12 +14,8 @@ $white = imagecolorallocate($image, 0xFF, 0xFF, 0xFF);
 //create an ellipse and fill it with white color    
 imagefilledellipse($image, 50, 50, 40, 30, $white);
 
-ob_start();
-imagegd($image);
-$img = ob_get_contents();
-ob_end_clean();
-
-echo md5(base64_encode($img));
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/imagefilledellipse_basic.png', $image);
 ?>
 --EXPECT--
-233beffe003a41d3c9e788039e3191dd
+The images are equal.

ext/gd/tests/imagefilltoborder_basic.phpt

@@ -21,13 +21,9 @@ imageellipse( $image, 50, 50, 50, 50, imagecolorallocate( $image, 0, 0, 0 ) );
 // Fill border
 imagefilltoborder( $image, 50, 50, imagecolorallocate( $image, 0, 0, 0 ), imagecolorallocate( $image, 255, 0, 0 ) );
 
-ob_start(); 
-imagegd( $image);
-$img = ob_get_contents(); 
-ob_end_clean();
-
-echo md5(base64_encode($img));
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/imagefilltoborder_basic.png', $image);
 
 ?> 
 --EXPECT-- 
-8185a06ccff03c2abeb99d5e3ed60e45
+The images are equal.

ext/gd/tests/imagegammacorrect_basic.phpt

@@ -21,15 +21,11 @@ $half =  imagefilledarc ( $image, 75, 75, 70, 70, 0, 180, $grey, IMG_ARC_PIE );
 $half2 =  imagefilledarc ( $image, 75, 75, 70, 70, 0, -180, $gray, IMG_ARC_PIE );
 
 $gamma = imagegammacorrect($image, 1, 5);
+var_dump((bool) $gamma);
 
-if ($gamma){
-	ob_start();
-	imagegd($image);
-	$img = ob_get_contents();
-	ob_end_clean();
-}
-
-echo md5(base64_encode($img));
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/imagegammacorrect_basic.png', $image);
 ?>
 --EXPECT--
-1f625723f9d27251a1f15b83a6a4bf55
+bool(true)
+The images are equal.

ext/gd/tests/imagegammacorrect_variation1.phpt

@@ -21,15 +21,11 @@ $half =  imagefilledarc ( $image, 75, 75, 70, 70, 0, 180, $grey, IMG_ARC_PIE );
 $half2 =  imagefilledarc ( $image, 75, 75, 70, 70, 0, -180, $gray, IMG_ARC_PIE );
 
 $gamma = imagegammacorrect($image, 1, 5);
+var_dump((bool) $gamma);
 
-if ($gamma){
-	ob_start();
-	imagegd($image);
-	$img = ob_get_contents();
-	ob_end_clean();
-}
-
-echo md5(base64_encode($img));
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/imagegammacorrect_variation1.png', $image);
 ?>
 --EXPECT--
-32fdb7b3675e4a9fd601c6a0645c88b3
+bool(true)
+The images are equal.

ext/gd/tests/imagelayereffect_basic.phpt

@@ -13,15 +13,11 @@ Rafael Dohms <rdohms [at] gmail [dot] com>
 $image = imagecreatetruecolor(180, 30);
 
 $layer = imagelayereffect($image, IMG_EFFECT_REPLACE);
+var_dump((bool) $layer);
 
-if ($layer){
-	ob_start();
-	imagegd($image);
-	$img = ob_get_contents();
-	ob_end_clean();
-}
-
-echo md5(base64_encode($img));
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/imagelayereffect_basic.png', $image);
 ?>
 --EXPECT--
-da884f488a851e0267a316ad232aee86
+bool(true)
+The images are equal.

ext/gd/tests/imagerectangle_basic.phpt

@@ -15,13 +15,8 @@ $image = imagecreatetruecolor( 100, 100 );
 // Draw a rectangle
 imagerectangle( $image, 0, 0, 50, 50, imagecolorallocate($image, 255, 255, 255) );
 
-ob_start(); 
-imagegd( $image );
-$img = ob_get_contents(); 
-ob_end_clean();
-
-echo md5(base64_encode($img));
-
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/imagerectangle_basic.png', $image);
 ?> 
 --EXPECT-- 
-e7f8ca8c63fb08b248f3ed6435983aed
+The images are equal.

ext/gd/tests/imagesetbrush_basic.phpt

@@ -26,12 +26,8 @@ imagesetbrush($mainimg, $img);
 // Draw a couple of brushes, each overlaying each
 imageline($mainimg, 50, 50, 50, 60, IMG_COLOR_BRUSHED);
 
-// Get output and generate md5 hash
-ob_start();
-imagegd($mainimg);
-$result_image = ob_get_contents();
-ob_end_clean();
-echo md5(base64_encode($result_image));
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/imagesetbrush_basic.png', $mainimg);
 ?>
 --EXPECT--
-2bb294c388d826cc9bba6c6fd31f265a
+The images are equal.

ext/gd/tests/imagesetthickness_basic.phpt

@@ -23,12 +23,8 @@ imagesetthickness($image, 5);
 // Draw the rectangle
 imagerectangle($image, 14, 14, 185, 85, $black);
 
-ob_start();
-imagegd($image);
-$img = ob_get_contents();
-ob_end_clean();
-
-echo md5(base64_encode($img));
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/imagesetthickness_basic.png', $image);
 ?>
 --EXPECT--
-1a6bc882772310d2e9b32cca2574236c
+The images are equal.

ext/gd/tests/imagestring_basic.phpt

@@ -14,12 +14,8 @@ $white = imagecolorallocate($image, 255,255,255);
 
 $result = imagestring($image, 1, 5, 5, 'String Text', $white);
 
-ob_start();
-imagegd($image);
-$img = ob_get_contents();
-ob_end_clean();
-
-echo md5(base64_encode($img));
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/imagestring_basic.png', $image);
 ?>
 --EXPECT--
-7f146e3cdcaf89c6b9d68ccbb44cf94e
+The images are equal.

ext/gd/tests/imagestringup_basic.phpt

@@ -14,12 +14,8 @@ $white = imagecolorallocate($image, 255,255,255);
 
 $result = imagestringup($image, 1, 5, 25, 'Str', $white);
 
-ob_start();
-imagegd($image);
-$img = ob_get_contents();
-ob_end_clean();
-
-echo md5(base64_encode($img));
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/imagestringup_basic.png', $image);
 ?>
 --EXPECT--
-7c55836800702bdd43b4c25d8ebcfcd0
+The images are equal.

ext/gd/tests/imagetruecolortopalette_basic.phpt

@@ -22,13 +22,9 @@ $half2 =  imagefilledarc ( $image, 75, 55, 80, 70, 0, -180, $b, IMG_ARC_PIE );
 
 var_dump(imagetruecolortopalette($image, true, 2));
 
-ob_start();
-imagegd($image);
-$img = ob_get_contents();
-ob_end_clean();
-
-echo md5(base64_encode($img));
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/imagetruecolortopalette_basic.png', $image);
 ?>
 --EXPECT--
 bool(true)
-17c901cb2217eb7647deed1c79d445de
+The images are equal.

ext/gd/tests/libgd00100.phpt

@@ -106,14 +106,10 @@ $points = array(
 );
 imagefilledpolygon($im, $points, 5, $black);
 
-ob_start();
-imagegd($im);
-$png = ob_get_contents();
-ob_end_clean();
-
-echo md5($png);
+include_once __DIR__ . '/func.inc';
+test_image_equals_file(__DIR__ . '/libgd00100.png', $im);
 
 imagedestroy($im);
 ?>
 --EXPECTF--
-df7253c765280396f303166f10ba9283
+The images are equal.