Fix #506: Additional parameters to tuple:unpack()

src/box/lua/tuple.lua

@@ -114,23 +114,38 @@ local tuple_totable_mt = {
     __serialize = 'seq'; -- enables flow mode for yaml
 }
 
-local function tuple_totable(tuple)
+local function tuple_totable(tuple, i, j)
     -- use a precreated iterator for tuple_next
     builtin.tuple_rewind(next_it, tuple)
-    local ret = {}
-    while true do
-        local field = builtin.tuple_next(next_it)
-        if field == nil then
-            break
+    local field
+    if i ~= nil then
+        if i < 1 then
+            error('tuple.totable: invalid second argument')
+        end
+        field = builtin.tuple_seek(next_it, i - 1)
+    else
+        i = 1
+        field = builtin.tuple_next(next_it)
+    end
+    if j ~= nil then
+        if j <= 0 then
+            error('tuple.totable: invalid third argument')
         end
+    else
+        j = 4294967295
+    end
+    local ret = {}
+    while field ~= nil and i <= j do
         local val = msgpackffi.decode_unchecked(field)
         table.insert(ret, val)
+        i = i + 1
+        field = builtin.tuple_next(next_it)
     end
     return setmetatable(ret, tuple_totable_mt)
 end
 
-local function tuple_unpack(tuple)
-    return unpack(tuple_totable(tuple))
+local function tuple_unpack(tuple, i, j)
+    return unpack(tuple_totable(tuple, i, j))
 end
 
 local function tuple_find(tuple, offset, val)

test/box/tuple.result

@@ -227,24 +227,92 @@ box.tuple.new{'x', 'y', 'z', {1, 2}, {c = 3, d = 4}, {e = 5, f = 6}}
 ---
 - ['x', 'y', 'z', [1, 2], {'c': 3, 'd': 4}, {'e': 5, 'f': 6}]
 ...
---
--- A test case for #107 "box.tuple.unpack asserts on extra arguments"
---
 t=box.tuple.new{'a','b','c'}
 ---
 ...
-t:unpack(5)
+t:totable()
+---
+- ['a', 'b', 'c']
+...
+t:unpack()
 ---
 - a
 - b
 - c
 ...
-t:unpack(1, 2, 3, 4, 5)
+t:totable(1)
+---
+- ['a', 'b', 'c']
+...
+t:unpack(1)
 ---
 - a
 - b
 - c
 ...
+t:totable(2)
+---
+- ['b', 'c']
+...
+t:unpack(2)
+---
+- b
+- c
+...
+t:totable(1, 3)
+---
+- ['a', 'b', 'c']
+...
+t:unpack(1, 3)
+---
+- a
+- b
+- c
+...
+t:totable(2, 3)
+---
+- ['b', 'c']
+...
+t:unpack(2, 3)
+---
+- b
+- c
+...
+t:totable(2, 4)
+---
+- ['b', 'c']
+...
+t:unpack(2, 4)
+---
+- b
+- c
+...
+t:totable(nil, 2)
+---
+- ['a', 'b']
+...
+t:unpack(nil, 2)
+---
+- a
+- b
+...
+t:totable(2, 1)
+---
+- []
+...
+t:unpack(2, 1)
+---
+...
+t:totable(0)
+---
+- error: '[string "-- tuple.lua (internal file)..."]:123: tuple.totable: invalid second
+    argument'
+...
+t:totable(1, 0)
+---
+- error: '[string "-- tuple.lua (internal file)..."]:132: tuple.totable: invalid third
+    argument'
+...
 --
 -- Check that tuple:totable correctly sets serializer hints
 --
@@ -735,12 +803,12 @@ t = box.tuple.new({'a', 'b', 'c', 'd', 'e'})
 ...
 t:update()
 ---
-- error: '[string "-- tuple.lua (internal file)..."]:157: Usage: tuple:update({ {
+- error: '[string "-- tuple.lua (internal file)..."]:172: Usage: tuple:update({ {
     op, field, arg}+ })'
 ...
 t:update(10)
 ---
-- error: '[string "-- tuple.lua (internal file)..."]:157: Usage: tuple:update({ {
+- error: '[string "-- tuple.lua (internal file)..."]:172: Usage: tuple:update({ {
     op, field, arg}+ })'
 ...
 t:update({})

test/box/tuple.test.lua

@@ -66,12 +66,26 @@ box.tuple.new{{1, 2}, 'x', 'y', 'z', {c = 3, d = 4}, {e = 5, f = 6}}
 box.tuple.new('x', 'y', 'z', {1, 2}, {c = 3, d = 4}, {e = 5, f = 6})
 box.tuple.new{'x', 'y', 'z', {1, 2}, {c = 3, d = 4}, {e = 5, f = 6}}
 
---
--- A test case for #107 "box.tuple.unpack asserts on extra arguments"
---
 t=box.tuple.new{'a','b','c'}
-t:unpack(5)
-t:unpack(1, 2, 3, 4, 5)
+t:totable()
+t:unpack()
+t:totable(1)
+t:unpack(1)
+t:totable(2)
+t:unpack(2)
+t:totable(1, 3)
+t:unpack(1, 3)
+t:totable(2, 3)
+t:unpack(2, 3)
+t:totable(2, 4)
+t:unpack(2, 4)
+t:totable(nil, 2)
+t:unpack(nil, 2)
+t:totable(2, 1)
+t:unpack(2, 1)
+
+t:totable(0)
+t:totable(1, 0)
 
 --
 -- Check that tuple:totable correctly sets serializer hints