[tarantool-patches] [PATCH v1 1/1] box: ability to omit box.cfg() call in sql

[Kirill Shcherbatov <kshcherbatov@tarantool.org>]

This makes possible to call box.sql.execute without pre-calling box.cfg.
Introduced metatable __index function for box.sql that  called when no
appropriate box.sql methods (execute, debug) is defined. It calls
box.cfg() itself that redefines box.sql table.

Closes #3266
---
 src/box/lua/load_cfg.lua | 15 +++++++++++++++
 test/box/cfg.result      | 17 +++++++++++++++++
 test/box/cfg.test.lua    | 10 ++++++++++
 3 files changed, 42 insertions(+)

diff --git a/src/box/lua/load_cfg.lua b/src/box/lua/load_cfg.lua
index 4ace1e1..781de3e 100644
--- a/src/box/lua/load_cfg.lua
+++ b/src/box/lua/load_cfg.lua
@@ -418,6 +418,21 @@ local function load_cfg(cfg)
 end
 box.cfg = load_cfg
 
+--
+-- gh-3266: box.cfg{} still not optional on 2.0 brach
+--
+-- This makes possible do box.sql.execute without calling box.cfg
+-- manually. The load_cfg call would overwrite following table and
+-- metatable.
+--
+box.sql = {}
+setmetatable(box.sql, {
+    __index = function(table, index)
+        load_cfg()
+        return box.sql[index]
+    end,
+})
+
 -- gh-810:
 -- hack luajit default cpath
 -- commented out because we fixed luajit to build properly, see
diff --git a/test/box/cfg.result b/test/box/cfg.result
index 14dceac..42a0a89 100644
--- a/test/box/cfg.result
+++ b/test/box/cfg.result
@@ -434,6 +434,23 @@ box.cfg{net_msg_max = old + 1000}
 box.cfg{net_msg_max = old}
 ---
 ...
+--
+-- gh-3266: box.cfg{} still not optional on 2.0 brach
+--
+-- box.sql defined with __index function in metatable overriten with first
+-- sql.cfg() call
+--
+box.cfg()
+---
+...
+assert(next(box.sql) ~= box.NULL)
+---
+- true
+...
+assert(getmetatable(box.sql) == box.NULL)
+---
+- true
+...
 test_run:cmd("clear filter")
 ---
 - true
diff --git a/test/box/cfg.test.lua b/test/box/cfg.test.lua
index 2d819c9..b1f4dc9 100644
--- a/test/box/cfg.test.lua
+++ b/test/box/cfg.test.lua
@@ -91,4 +91,14 @@ box.cfg{net_msg_max = 2}
 box.cfg{net_msg_max = old + 1000}
 box.cfg{net_msg_max = old}
 
+--
+-- gh-3266: box.cfg{} still not optional on 2.0 brach
+--
+-- box.sql defined with __index function in metatable overriten with first
+-- sql.cfg() call
+--
+box.cfg()
+assert(next(box.sql) ~= box.NULL)
+assert(getmetatable(box.sql) == box.NULL)
+
 test_run:cmd("clear filter")
-- 
2.7.4