Fix #502: box.slab.info() excessively sparse array

src/box/lua/slab.cc

@@ -87,6 +87,7 @@ lbox_slab_info(struct lua_State *L)
 	lua_newtable(L);
 	lua_pushstring(L, "slabs");
 	lua_newtable(L);
+	luaL_setmaphint(L, -1);
 	small_stats(&talloc, &totals, small_stats_lua_cb, L);
 	lua_settable(L, -3);
 

test/box/misc.result

@@ -120,7 +120,7 @@ t;
   - 'fieldno : 1'
 ...
 ----------------
--- # box.space
+-- # box.slab
 ----------------
 string.match(tostring(box.slab.info()), '^table:') ~= nil;
 ---
@@ -154,6 +154,13 @@ t;
   - arena_size
   - slabs
 ...
+--
+-- gh-502: box.slab.info() excessively sparse array
+--
+type(require('yaml').encode(box.slab.info()));
+---
+- string
+...
 ----------------
 -- # box.error
 ----------------

test/box/misc.test.lua

@@ -50,7 +50,7 @@ end;
 t;
 
 ----------------
--- # box.space
+-- # box.slab
 ----------------
 string.match(tostring(box.slab.info()), '^table:') ~= nil;
 box.slab.info().arena_used >= 0;
@@ -62,6 +62,11 @@ for k, v in pairs(box.slab.info()) do
 end;
 t;
 
+--
+-- gh-502: box.slab.info() excessively sparse array
+--
+type(require('yaml').encode(box.slab.info()));
+
 ----------------
 -- # box.error
 ----------------