Bug #77700 [NEW]: Writing truecolor images as GIF ignores interlace flag

From: cmb Operating system: * PHP version: 7.2Git-2019-03-05 (Git) Package: GD related Bug Type: Bug Bug description:Writing truecolor images as GIF ignores interlace flag Description: ------------ Since GIF does not support truecolor images, a palette version of the image is created with gdImageCreatePaletteFromTrueColor() internally. When actually converting to GIF, our bundled libgd uses the interlace flag of the palette image, although it is not retained by gdImageCreatePaletteFromTrueColor(). Upstream libgd correctly uses the interlace flag of the original (truecolor) image instead. Test script: --------------- <?php $im = imagecreatetruecolor(10, 10); imagefilledrectangle($im, 0, 0, 9, 9, imagecolorallocate($im, 255, 255, 255)); imageinterlace($im, 1); imagegif($im, __DIR__ . '/test.gif'); $im = imagecreatefromgif(__DIR__ . '/test.gif'); var_dump(imageinterlace($im)); Expected result: ---------------- int(1) Actual result: -------------- int(0) -- Edit bug report at https://bugs.php.net/bug.php?id=77700&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=77700&r=trysnapshot54 Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=77700&r=trysnapshot55 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=77700&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=77700&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=77700&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=77700&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=77700&r=needscript Try newer version: https://bugs.php.net/fix.php?id=77700&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=77700&r=support Expected behavior: https://bugs.php.net/fix.php?id=77700&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=77700&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=77700&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=77700&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=77700&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=77700&r=dst IIS Stability: https://bugs.php.net/fix.php?id=77700&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=77700&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=77700&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=77700&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=77700&r=mysqlcfg