Bug #70904 [NEW]: `yield from` incorrectly marks valid generator as finished

From: srice at fb dot com Operating system: Linux PHP version: 7.0.0RC7 Package: PHP Language Specification Bug Type: Bug Bug description:yield from incorrectly marks valid generator as finished Description: ------------ The current implementation of the valid method doesnt properly take into account the possibility that the inner generator could be executed outside of the context of the outer generator. In this case, its saying that the outer generator isnt valid because the inner generator isnt valid, but in fact the outer generator still has more to execute. Test script: --------------- <?php function g1() { yield 1; yield 2; } function g2($g1) { yield from $g1; echo "!\n"; yield 3; } $g1 = g1(); $g2 = g2($g1); while ($g2->valid()) { var_dump($g2->current()); $g1->next(); } Expected result: ---------------- I would expect the following: int(1) int(2) NULL NULL NULL ...(infinite loop) I say this because g2 got primed to the yield from statement, so it should be returning for current whatever g1 is returning for current. For a finished generator, this would be NULL. Actual result: -------------- int(1) int(2) -- Edit bug report at https://bugs.php.net/bug.php?id=70904&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=70904&r=trysnapshot54 Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=70904&r=trysnapshot55 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=70904&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=70904&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=70904&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=70904&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=70904&r=needscript Try newer version: https://bugs.php.net/fix.php?id=70904&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=70904&r=support Expected behavior: https://bugs.php.net/fix.php?id=70904&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=70904&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=70904&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=70904&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=70904&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=70904&r=dst IIS Stability: https://bugs.php.net/fix.php?id=70904&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=70904&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=70904&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=70904&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=70904&r=mysqlcfg