Disallow closing a generator during its execution

If a generator is closed while it is running an E_WARNING is thrown and the
call is ignored. Maybe a fatal error should be thrown instead?

2 files changed, 17 insertions, 0 deletions

diff --git a/Zend/zend_generators.c b/Zend/zend_generators.c
index 487975e23e..bccbb48ca4 100644
--- a/Zend/zend_generators.c
+++ b/Zend/zend_generators.c
@@ -300,6 +300,8 @@ static zend_object_value zend_generator_create(zend_class_entry *class_type TSRM
 	/* The key will be incremented on first use, so it'll start at 0 */
 	generator->largest_used_integer_key = -1;
 
+	generator->is_currently_running = 0;
+
 	zend_object_std_init(&generator->std, class_type TSRMLS_CC);
 
 	object.handle = zend_objects_store_put(generator, NULL,
@@ -339,6 +341,8 @@ static void zend_generator_resume(zend_generator *generator TSRMLS_DC) /* {{{ */
 		zend_class_entry *original_scope = EG(scope);
 		zend_class_entry *original_called_scope = EG(called_scope);
 
+		zend_bool original_is_currently_running = generator->is_currently_running;
+
 		/* Remember the current stack position so we can back up pushed args */
 		generator->original_stack_top = zend_vm_stack_top(TSRMLS_C);
 
@@ -363,6 +367,8 @@ static void zend_generator_resume(zend_generator *generator TSRMLS_DC) /* {{{ */
 		EG(scope) = generator->execute_data->current_scope;
 		EG(called_scope) = generator->execute_data->current_called_scope;
 
+		generator->is_currently_running = 1;
+
 		/* We want the backtrace to look as if the generator function was
 		 * called from whatever method we are current running (e.g. next()).
 		 * The first prev_execute_data contains an additional stack frame,
@@ -387,6 +393,8 @@ static void zend_generator_resume(zend_generator *generator TSRMLS_DC) /* {{{ */
 		EG(scope) = original_scope;
 		EG(called_scope) = original_called_scope;
 
+		generator->is_currently_running = original_is_currently_running;
+
 		/* The stack top before and after the execution differ, i.e. there are
 		 * arguments pushed to the stack. */
 		if (generator->original_stack_top != zend_vm_stack_top(TSRMLS_C)) {
@@ -549,6 +557,11 @@ ZEND_METHOD(Generator, close)
 
 	generator = (zend_generator *) zend_object_store_get_object(getThis() TSRMLS_CC);
 
+	if (generator->is_currently_running) {
+		zend_error(E_WARNING, "A generator cannot be closed while it is running");
+		return;
+	}
+
 	zend_generator_close(generator, 0 TSRMLS_CC);
 }
 /* }}} */
diff --git a/Zend/zend_generators.h b/Zend/zend_generators.h
index 89193bbe6e..73d85287a7 100644
--- a/Zend/zend_generators.h
+++ b/Zend/zend_generators.h
@@ -46,6 +46,10 @@ typedef struct _zend_generator {
 	temp_variable *send_target;
 	/* Largest used integer key for auto-incrementing keys */
 	long largest_used_integer_key;
+
+	/* We need to know whether the generator is currently executed to avoid it
+	 * being closed while still running */
+	zend_bool is_currently_running;
 } zend_generator;
 
 extern ZEND_API zend_class_entry *zend_ce_generator;