add IMAGICK_NOT_EMPTY macro

Author: remicollet

imagickdraw_class.c

@@ -1315,8 +1315,7 @@ PHP_METHOD(ImagickDraw, composite)
 
 	intern = Z_IMAGICK_P(magick_obj);
 
-	if (php_imagick_ensure_not_empty (intern->magick_wand) == 0)
-		RETURN_THROWS();
+	IMAGICK_NOT_EMPTY(intern);
 
 	internd = Z_IMAGICKDRAW_P(getThis());
 	status = DrawComposite(internd->drawing_wand, compose, x, y, width, height, intern->magick_wand);

php_imagick_macros.h

@@ -43,7 +43,13 @@
 #define IMAGICK_KERNEL_NOT_NULL_EMPTY(kernel) \
 	if (kernel->kernel_info == NULL) { \
 		zend_throw_exception(php_imagickkernel_exception_class_entry, "ImagickKernel is empty, cannot be used", (long)0 TSRMLS_CC); \
-		RETURN_NULL(); \
+		RETURN_THROWS(); \
 	}
 
+#define IMAGICK_NOT_EMPTY(wand) \
+	if (php_imagick_ensure_not_empty (wand->magick_wand) == 0) { \
+		RETURN_THROWS(); \
+	}
+
+
 #endif /* PHP_IMAGICK_MACROS_H */