sql: move autoincrement in vdbe

This patch expands changes made in issue #2981. Now NULL
in primary key always replaced by generated value inside
of vdbe. It allows us to get last_insert_id with easy.

Part of ...

src/box/sql/insert.c

@@ -656,9 +656,7 @@ sqlite3Insert(Parse * pParse,	/* Parser context */
 			if (j < 0 || nColumn == 0
 			    || (pColumn && j >= pColumn->nId)) {
 				if (i == (int) autoinc_fieldno) {
-					sqlite3VdbeAddOp2(v,
-							  OP_NextAutoincValue,
-							  pTab->def->id,
+					sqlite3VdbeAddOp2(v, OP_Null, 0,
 							  iRegStore);
 					continue;
 				}
@@ -739,7 +737,14 @@ sqlite3Insert(Parse * pParse,	/* Parser context */
 						iRegStore);
 			}
 		}
-
+		/*
+		 * Replace NULL in PK with autoincrement by
+		 * generated value.
+		 */
+		if ((int) autoinc_fieldno >= 0) {
+			sqlite3VdbeAddOp2(v, OP_NextAutoincValue, pTab->def->id,
+					  regData + (int) autoinc_fieldno);
+		}
 		/*
 		 * Generate code to check constraints and process
 		 * final insertion.

src/box/sql/vdbe.c

@@ -1157,6 +1157,10 @@ case OP_NextAutoincValue: {
 	assert(pOp->p1 > 0);
 	assert(pOp->p2 > 0);
 
+	pIn2 = &p->aMem[pOp->p2];
+	if ((pIn2->flags & MEM_Null) == 0)
+		break;
+
 	struct space *space = space_by_id(pOp->p1);
 	if (space == NULL) {
 		rc = SQL_TARANTOOL_ERROR;
@@ -3755,7 +3759,7 @@ case OP_FCopy: {     /* out2 */
 
 	if ((pOp->p3 & OPFLAG_NOOP_IF_NULL) && (pIn1->flags & MEM_Null)) {
 		pOut = &aMem[pOp->p2];
-		if (pOut->flags & MEM_Undefined) pOut->flags = MEM_Null;
+		pOut->flags = MEM_Null;
 		/* Flag is set and register is NULL -> do nothing  */
 	} else {
 		assert(memIsValid(pIn1));

test/sql/gh-2981-check-autoinc.result

@@ -19,6 +19,9 @@ box.sql.execute("CREATE TABLE t2 (s1 INTEGER PRIMARY KEY AUTOINCREMENT, s2 INTEG
 box.sql.execute("CREATE TABLE t3 (s1 INTEGER PRIMARY KEY AUTOINCREMENT, s2 INTEGER, CHECK (s1 < 10));");
 ---
 ...
+box.sql.execute("CREATE TABLE t4 (s1 INTEGER PRIMARY KEY AUTOINCREMENT, s2 INTEGER, CHECK (s1 <> 19));");
+---
+...
 box.sql.execute("insert into t1 values (18, null);")
 ---
 ...
@@ -47,6 +50,13 @@ box.sql.execute("insert into t3(s2) values (null)")
 ---
 - error: 'CHECK constraint failed: T3'
 ...
+box.sql.execute("insert into t4 values (18, null);")
+---
+...
+box.sql.execute("insert into t4 values (null, null);")
+---
+- error: 'CHECK constraint failed: T4'
+...
 box.sql.execute("DROP TABLE t1")
 ---
 ...
@@ -56,3 +66,6 @@ box.sql.execute("DROP TABLE t2")
 box.sql.execute("DROP TABLE t3")
 ---
 ...
+box.sql.execute("DROP TABLE t4")
+---
+...

test/sql/gh-2981-check-autoinc.test.lua

@@ -7,6 +7,7 @@ box.cfg{}
 box.sql.execute("CREATE TABLE t1 (s1 INTEGER PRIMARY KEY AUTOINCREMENT, s2 INTEGER, CHECK (s1 <> 19));");
 box.sql.execute("CREATE TABLE t2 (s1 INTEGER PRIMARY KEY AUTOINCREMENT, s2 INTEGER, CHECK (s1 <> 19 AND s1 <> 25));");
 box.sql.execute("CREATE TABLE t3 (s1 INTEGER PRIMARY KEY AUTOINCREMENT, s2 INTEGER, CHECK (s1 < 10));");
+box.sql.execute("CREATE TABLE t4 (s1 INTEGER PRIMARY KEY AUTOINCREMENT, s2 INTEGER, CHECK (s1 <> 19));");
 
 box.sql.execute("insert into t1 values (18, null);")
 box.sql.execute("insert into t1(s2) values (null);")
@@ -19,7 +20,10 @@ box.sql.execute("insert into t2(s2) values (null);")
 box.sql.execute("insert into t3 values (9, null)")
 box.sql.execute("insert into t3(s2) values (null)")
 
+box.sql.execute("insert into t4 values (18, null);")
+box.sql.execute("insert into t4 values (null, null);")
+
 box.sql.execute("DROP TABLE t1")
 box.sql.execute("DROP TABLE t2")
 box.sql.execute("DROP TABLE t3")
-
+box.sql.execute("DROP TABLE t4")