[Tarantool-patches] [PATCH v2 5/6] alter: disallow creation of SQL built-in function

[Mergen Imeev via Tarantool-patches <tarantool-patches@dev.tarantool.org>]

This patch prohibits creation of user-defined functions with SQL_BUILTIN
engine.

Closes #6106
---
 src/box/alter.cc            | 38 +++++++++++++++++++++++++++++++++++++
 test/box/function1.result   |  7 ++++++-
 test/box/function1.test.lua |  3 +++
 3 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/src/box/alter.cc b/src/box/alter.cc
index 217b882ba..fd9921ae0 100644
--- a/src/box/alter.cc
+++ b/src/box/alter.cc
@@ -3213,6 +3213,36 @@ on_replace_dd_user(struct trigger * /* trigger */, void *event)
 	return 0;
 }
 
+/**
+ * Check if the version of the data dictionary is lower than 2.9.0 and return
+ * new func def if it is the case. If it is the case, then it is possible to
+ * insert values with the "SQL_BUILTIN" language into _func, otherwise it is
+ * prohibited. This is for upgradeability from 2.1.3 to 2.3.0. Since all we need
+ * is to allow such inserts, we set func def to its default values.
+ */
+static int
+func_def_new_sql_built_in(struct func_def *def)
+{
+	if (dd_version_id >= version_id(2, 9, 0)) {
+		diag_set(ClientError, ER_FUNCTION_LANGUAGE, "SQL_BUILTIN",
+			 def->name);
+		return -1;
+	}
+	def->body = NULL;
+	def->comment = NULL;
+	def->setuid = 1;
+	def->is_deterministic = false;
+	def->is_sandboxed = false;
+	def->param_count = 0;
+	def->returns = FIELD_TYPE_ANY;
+	def->aggregate = FUNC_AGGREGATE_NONE;
+	def->language = FUNC_LANGUAGE_LUA;
+	def->exports.lua = true;
+	def->exports.sql = true;
+	func_opts_create(&def->opts);
+	return 0;
+}
+
 /**
  * Get function identifiers from a tuple.
  *
@@ -3344,6 +3374,14 @@ func_def_new_from_tuple(struct tuple *tuple)
 				  language, def->name);
 			return NULL;
 		}
+		if (def->language == FUNC_LANGUAGE_SQL_BUILTIN) {
+			if (func_def_new_sql_built_in(def) != 0)
+				return NULL;
+			if (func_def_check(def) != 0)
+				return NULL;
+			def_guard.is_active = false;
+			return def;
+		}
 	} else {
 		/* Lua is the default. */
 		def->language = FUNC_LANGUAGE_LUA;
diff --git a/test/box/function1.result b/test/box/function1.result
index a49a133f7..a1c89850d 100644
--- a/test/box/function1.result
+++ b/test/box/function1.result
@@ -372,7 +372,7 @@ c:close()
 box.schema.func.create('WAITFOR', {language = 'SQL_BUILTIN', \
 	param_list = {'integer'}, returns = 'integer',exports = {'SQL'}})
 ---
-- error: 'Failed to create function ''WAITFOR'': given built-in is not predefined'
+- error: Unsupported language 'SQL_BUILTIN' specified for function 'WAITFOR'
 ...
 test_run:cmd("setopt delimiter ';'")
 ---
@@ -1078,3 +1078,8 @@ box.func['test'].is_multikey == true
 box.func['test']:drop()
 ---
 ...
+-- gh-6106: Check that user-defined functions cannot have SQL_BUILTIN engine.
+box.schema.func.create("ABS", {language = 'SQL_BUILTIN', returns = 'integer'})
+---
+- error: Unsupported language 'SQL_BUILTIN' specified for function 'ABS'
+...
diff --git a/test/box/function1.test.lua b/test/box/function1.test.lua
index 4fdd48520..e635b6e18 100644
--- a/test/box/function1.test.lua
+++ b/test/box/function1.test.lua
@@ -389,3 +389,6 @@ box.func.LUA:call({"return 1 + 1"})
 box.schema.func.create('test', {body = "function(tuple) return tuple end", is_deterministic = true, opts = {is_multikey = true}})
 box.func['test'].is_multikey == true
 box.func['test']:drop()
+
+-- gh-6106: Check that user-defined functions cannot have SQL_BUILTIN engine.
+box.schema.func.create("ABS", {language = 'SQL_BUILTIN', returns = 'integer'})
-- 
2.25.1