[tarantool-patches] [PATCH] box: fix bug with module_reload() without box.cfg{}

[Roman Khabibov <roman.habibov@tarantool.org>]

Fix bug with segfault when use module_reload() before box.cfg{}.

Closes #3770

Branch: https://github.com/tarantool/tarantool/tree/romanhabibov/gh-3770-module-reload
Issue: https://github.com/tarantool/tarantool/issues/3770
---
 src/box/func.c                | 3 +++
 test/box/func_reload.result   | 9 +++++++++
 test/box/func_reload.test.lua | 5 +++++
 3 files changed, 17 insertions(+)

diff --git a/src/box/func.c b/src/box/func.c
index a817851fd..ee6dd55dc 100644
--- a/src/box/func.c
+++ b/src/box/func.c
@@ -301,6 +301,9 @@ module_sym(struct module *module, const char *name)
 int
 module_reload(const char *package, const char *package_end, struct module **module)
 {
+	if (!modules)
+		return -1;
+
 	struct module *old_module = module_cache_find(package, package_end);
 	if (old_module == NULL) {
 		/* Module wasn't loaded - do nothing. */
diff --git a/test/box/func_reload.result b/test/box/func_reload.result
index b024cd143..e35ca41e2 100644
--- a/test/box/func_reload.result
+++ b/test/box/func_reload.result
@@ -1,3 +1,12 @@
+-- gh-3770 Check no segfault with module_reload() without box.cfg{}.
+box.internal.module_reload('')
+---
+- error: Module '' does not exist
+...
+box.internal.module_reload('xxx')
+---
+- error: Module 'xxx' does not exist
+...
 fio  = require('fio')
 ---
 ...
diff --git a/test/box/func_reload.test.lua b/test/box/func_reload.test.lua
index 8906898ec..00fe8cf48 100644
--- a/test/box/func_reload.test.lua
+++ b/test/box/func_reload.test.lua
@@ -1,3 +1,8 @@
+-- gh-3770 Check no segfault with module_reload() without box.cfg{}.
+
+box.internal.module_reload('')
+box.internal.module_reload('xxx')
+
 fio  = require('fio')
 net = require('net.box')
 fiber = require('fiber')
-- 
2.17.1