[Tarantool-patches] [PATCH 2/3] box: forbid to update/replace _space_sequence

[Vladislav Shpilevoy <v.shpilevoy@tarantool.org>]

Anyway this does not work for generated sequences. A proper
support of update would complicate the code and won't give
anything useful.

Part of #4771
---
 src/box/alter.cc           |  8 ++++++--
 test/box/sequence.result   | 19 +++++++++++++++++++
 test/box/sequence.test.lua |  9 +++++++++
 3 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/src/box/alter.cc b/src/box/alter.cc
index 64af71c61..50121c79c 100644
--- a/src/box/alter.cc
+++ b/src/box/alter.cc
@@ -4713,9 +4713,13 @@ on_replace_dd_space_sequence(struct trigger * /* trigger */, void *event)
 		return -1;
 	}
 
+	if ((stmt->new_tuple != NULL) == (stmt->old_tuple != NULL)) {
+		diag_set(ClientError, ER_UNSUPPORTED,
+			 "space \"_space_sequence\"", "update");
+		return -1;
+	}
+
 	enum priv_type priv_type = stmt->new_tuple ? PRIV_C : PRIV_D;
-	if (stmt->new_tuple && stmt->old_tuple)
-		priv_type = PRIV_A;
 
 	/* Check we have the correct access type on the sequence.  * */
 	if (is_generated || !stmt->new_tuple) {
diff --git a/test/box/sequence.result b/test/box/sequence.result
index 917952909..0a6cfee2c 100644
--- a/test/box/sequence.result
+++ b/test/box/sequence.result
@@ -2270,3 +2270,22 @@ sq:next() -- 2
 sq:drop()
 ---
 ...
+--
+-- Update on _space_sequence is forbidden.
+--
+s = box.schema.create_space('test')
+---
+...
+pk = s:create_index('pk', {sequence = true})
+---
+...
+t = box.space._space_sequence:get({s.id})
+---
+...
+box.space._space_sequence:update({s.id}, {{'=', 2, t[2]}})
+---
+- error: space "_space_sequence" does not support update
+...
+s:drop()
+---
+...
diff --git a/test/box/sequence.test.lua b/test/box/sequence.test.lua
index b0ec020ed..8e00571e5 100644
--- a/test/box/sequence.test.lua
+++ b/test/box/sequence.test.lua
@@ -771,3 +771,12 @@ sq:next() -- 1
 box.begin() box.space._sequence_data:delete{sq.id} box.rollback()
 sq:next() -- 2
 sq:drop()
+
+--
+-- Update on _space_sequence is forbidden.
+--
+s = box.schema.create_space('test')
+pk = s:create_index('pk', {sequence = true})
+t = box.space._space_sequence:get({s.id})
+box.space._space_sequence:update({s.id}, {{'=', 2, t[2]}})
+s:drop()
-- 
2.21.1 (Apple Git-122.3)