fix gh-464 lua iterators fix

src/box/index.h

@@ -88,6 +88,7 @@ struct iterator {
 	int sc_version;
 	uint32_t space_id;
 	uint32_t index_id;
+	class Index *index;
 };
 
 static inline void

src/box/lua/index.cc

@@ -98,6 +98,7 @@ boxffi_index_iterator(uint32_t space_id, uint32_t index_id, int type,
 		it->sc_version = sc_version;
 		it->space_id = space_id;
 		it->index_id = index_id;
+		it->index = index;
 		return it;
 	} catch (Exception *) {
 		if (it)
@@ -113,6 +114,8 @@ boxffi_iterator_next(struct iterator *itr)
 	if (itr->sc_version != sc_version) {
 		try {
 			Index *index = check_index(itr->space_id, itr->index_id);
+			if (index != itr->index)
+				return NULL;
 			if (index->sc_version > itr->sc_version)
 				return NULL;
 			itr->sc_version = sc_version;

test/big/iterator.result

@@ -911,3 +911,52 @@ gen(param, state)
 space:drop()
 ---
 ...
+-------------------------------------------------------------------------------
+-- Iterator: https://github.com/tarantool/tarantool/issues/464
+-- Iterator safety after changing schema
+-------------------------------------------------------------------------------
+space = box.schema.create_space('test', {temporary=true})
+---
+...
+space:create_index('primary', {type='HASH',unique=true})
+---
+...
+space:create_index('t1', {type='TREE',unique=true})
+---
+...
+space:create_index('t2', {type='TREE',unique=true})
+---
+...
+box.space.test:insert{0}
+---
+- [0]
+...
+box.space.test:insert{1}
+---
+- [1]
+...
+gen, param, state = space.index.t1:pairs({}, {iterator = box.index.ALL})
+---
+...
+print(gen(param, state))
+---
+...
+id = s.index.t1.id
+---
+- error: '[string "id = s.index.t1.id "]:1: attempt to index field ''t1'' (a nil value)'
+...
+box.schema.index.drop(s.id, id)
+---
+- error: Illegal parameters, index_id should be a number
+...
+box.schema.index.alter(s.id, s.index.t2.id, {id = id})
+---
+- error: '[string "return box.schema.index.alter(s.id, s.index.t..."]:1: attempt to
+    index field ''t2'' (a nil value)'
+...
+print(gen(param, state))
+---
+...
+space:drop()
+---
+...

test/big/iterator.test.lua

@@ -169,3 +169,28 @@ index_space:delete{space.id, space.index['i1'].id}
 gen(param, state)
 
 space:drop()
+
+-------------------------------------------------------------------------------
+-- Iterator: https://github.com/tarantool/tarantool/issues/464
+-- Iterator safety after changing schema
+-------------------------------------------------------------------------------
+
+space = box.schema.create_space('test', {temporary=true})
+space:create_index('primary', {type='HASH',unique=true})
+space:create_index('t1', {type='TREE',unique=true})
+space:create_index('t2', {type='TREE',unique=true})
+
+box.space.test:insert{0}
+box.space.test:insert{1}
+
+gen, param, state = space.index.t1:pairs({}, {iterator = box.index.ALL})
+print(gen(param, state))
+
+id = s.index.t1.id
+box.schema.index.drop(s.id, id)
+box.schema.index.alter(s.id, s.index.t2.id, {id = id})
+
+print(gen(param, state))
+
+space:drop()
+