Fix GH-11121: ReflectionFiber segfault

Author: danog

Zend/zend_fibers.c

@@ -388,6 +388,10 @@ ZEND_API void zend_fiber_switch_context(zend_fiber_transfer *transfer)
 
 	zend_observer_fiber_switch_notify(from, to);
 
+	if (from->kind == zend_ce_fiber) {
+		zend_fiber_from_context(from)->execute_data = EG(current_execute_data);
+	}
+
 	zend_fiber_capture_vm_state(&state);
 
 	to->status = ZEND_FIBER_STATUS_RUNNING;

ext/reflection/tests/ReflectionFiber_bug_gh11121_1.phpt

@@ -0,0 +1,62 @@
+--TEST--
+GH-11121: Segfault when using ReflectionFiber
+--FILE--
+<?php
+function f() {
+    Fiber::suspend();
+}
+
+function g() {
+    (new Fiber(function() {
+        global $f;
+        var_dump((new ReflectionFiber($f))->getTrace());
+    }))->start();
+}
+
+$f = new Fiber(function() { f(); max(...[1,2,3,4,5,6,7,8,9,10,11,12]); g(); });
+$f->start();
+$f->resume();
+
+?>
+--EXPECTF--
+array(3) {
+  [0]=>
+  array(7) {
+    ["file"]=>
+    string(%d) "%sReflectionFiber_bug_gh11121_1.php"
+    ["line"]=>
+    int(10)
+    ["function"]=>
+    string(5) "start"
+    ["class"]=>
+    string(5) "Fiber"
+    ["object"]=>
+    object(Fiber)#3 (0) {
+    }
+    ["type"]=>
+    string(2) "->"
+    ["args"]=>
+    array(0) {
+    }
+  }
+  [1]=>
+  array(4) {
+    ["file"]=>
+    string(%d) "%sReflectionFiber_bug_gh11121_1.php"
+    ["line"]=>
+    int(13)
+    ["function"]=>
+    string(1) "g"
+    ["args"]=>
+    array(0) {
+    }
+  }
+  [2]=>
+  array(2) {
+    ["function"]=>
+    string(9) "{closure}"
+    ["args"]=>
+    array(0) {
+    }
+  }
+}

ext/reflection/tests/ReflectionFiber_bug_gh11121_2.phpt

@@ -0,0 +1,63 @@
+--TEST--
+GH-11121: Segfault when using ReflectionFiber
+--FILE--
+<?php
+
+function f() {
+    Fiber::suspend();
+}
+
+function g() {
+    (new Fiber(function() {
+        global $f;
+        var_dump((new ReflectionFiber($f))->getTrace());
+    }))->start();
+}
+
+$f = new Fiber(function() { f(); g(); });
+$f->start();
+$f->resume();
+
+?>
+--EXPECTF--
+array(3) {
+  [0]=>
+  array(7) {
+    ["file"]=>
+    string(%d) "%sReflectionFiber_bug_gh11121_2.php"
+    ["line"]=>
+    int(11)
+    ["function"]=>
+    string(5) "start"
+    ["class"]=>
+    string(5) "Fiber"
+    ["object"]=>
+    object(Fiber)#3 (0) {
+    }
+    ["type"]=>
+    string(2) "->"
+    ["args"]=>
+    array(0) {
+    }
+  }
+  [1]=>
+  array(4) {
+    ["file"]=>
+    string(%d) "%sReflectionFiber_bug_gh11121_2.php"
+    ["line"]=>
+    int(14)
+    ["function"]=>
+    string(1) "g"
+    ["args"]=>
+    array(0) {
+    }
+  }
+  [2]=>
+  array(2) {
+    ["function"]=>
+    string(9) "{closure}"
+    ["args"]=>
+    array(0) {
+    }
+  }
+}