[tarantool-patches] [PATCH v1 1/2] sql: restrict nullable action definitions

[Kirill Shcherbatov <kshcherbatov@tarantool.org>]

This patch dissallows define multiple "NULL", "NOT NULL"
options per column and fixes silent implicit behavior
for invalid "NULL PRIMARY KEY" construction.

Closes #3473.
---
 src/box/alter.cc              |  1 +
 src/box/field_def.c           |  1 +
 src/box/field_def.h           |  3 ++-
 src/box/sql/build.c           | 46 +++++++++++++++++++++++++++++++++++++++----
 src/box/sql/parse.y           |  2 +-
 test/sql/on-conflict.result   | 13 ++++++++++++
 test/sql/on-conflict.test.lua |  6 ++++++
 7 files changed, 66 insertions(+), 6 deletions(-)

diff --git a/src/box/alter.cc b/src/box/alter.cc
index 7b6bd1a..3791ac7 100644
--- a/src/box/alter.cc
+++ b/src/box/alter.cc
@@ -390,6 +390,7 @@ field_def_decode(struct field_def *field, const char **data,
 				     "nullable action",
 				     fieldno + TUPLE_INDEX_BASE));
 	}
+	assert(field->nullable_action != ON_CONFLICT_ACTION_UNDEFINED);
 	if (!((field->is_nullable && field->nullable_action ==
 	       ON_CONFLICT_ACTION_NONE)
 	      || (!field->is_nullable
diff --git a/src/box/field_def.c b/src/box/field_def.c
index 8dbead6..70a9e46 100644
--- a/src/box/field_def.c
+++ b/src/box/field_def.c
@@ -46,6 +46,7 @@ const char *field_type_strs[] = {
 };
 
 const char *on_conflict_action_strs[] = {
+	/* [ON_CONFLICT_ACTION_UNDEFINED]= */ "undefined",
 	/* [ON_CONFLICT_ACTION_NONE]     = */ "none",
 	/* [ON_CONFLICT_ACTION_ROLLBACK] = */ "rollback",
 	/* [ON_CONFLICT_ACTION_ABORT]    = */ "abort",
diff --git a/src/box/field_def.h b/src/box/field_def.h
index 05f80d4..c35e0b8 100644
--- a/src/box/field_def.h
+++ b/src/box/field_def.h
@@ -60,7 +60,8 @@ enum field_type {
 };
 
 enum on_conflict_action {
-	ON_CONFLICT_ACTION_NONE = 0,
+	ON_CONFLICT_ACTION_UNDEFINED = 0,
+	ON_CONFLICT_ACTION_NONE,
 	ON_CONFLICT_ACTION_ROLLBACK,
 	ON_CONFLICT_ACTION_ABORT,
 	ON_CONFLICT_ACTION_FAIL,
diff --git a/src/box/sql/build.c b/src/box/sql/build.c
index 53c20a6..946b10c 100644
--- a/src/box/sql/build.c
+++ b/src/box/sql/build.c
@@ -653,7 +653,7 @@ sqlite3AddColumn(Parse * pParse, Token * pName, Token * pType)
 	struct field_def *column_def = &p->def->fields[p->def->field_count];
 	memcpy(column_def, &field_def_default, sizeof(field_def_default));
 	column_def->name = z;
-	column_def->nullable_action = ON_CONFLICT_ACTION_NONE;
+	column_def->nullable_action = ON_CONFLICT_ACTION_UNDEFINED;
 	column_def->is_nullable = true;
 
 	if (pType->n == 0) {
@@ -701,9 +701,22 @@ sqlite3AddNotNull(Parse * pParse, int onError)
 	p = pParse->pNewTable;
 	if (p == 0 || NEVER(p->def->field_count < 1))
 		return;
-	p->def->fields[p->def->field_count - 1].nullable_action = (u8)onError;
-	p->def->fields[p->def->field_count - 1].is_nullable =
-		action_is_nullable(onError);
+	struct field_def *field = &p->def->fields[p->def->field_count - 1];
+	if (field->nullable_action != ON_CONFLICT_ACTION_UNDEFINED) {
+		/* Prevent defining nullable_action many times. */
+		const char *err_msg =
+			tt_sprintf("NULL declaration for column '%s' of table "
+				   "'%s' has been already set to '%s'",
+				   field->name, p->def->name,
+				   on_conflict_action_strs[field->
+							   nullable_action]);
+		diag_set(ClientError, ER_SQL, err_msg);
+		pParse->rc = SQL_TARANTOOL_ERROR;
+		pParse->nErr++;
+		return;
+	}
+	field->nullable_action = (u8)onError;
+	field->is_nullable = action_is_nullable(onError);
 }
 
 /*
@@ -1728,6 +1741,31 @@ sqlite3EndTable(Parse * pParse,	/* Parse context */
 		p->def->id = SQLITE_PAGENO_TO_SPACEID(p->tnum);
 	}
 
+	/* Set default on_nullable action if required. */
+	for (uint32_t i = 0; i < p->def->field_count; i++) {
+		if (p->def->fields[i].nullable_action ==
+		    ON_CONFLICT_ACTION_UNDEFINED) {
+			p->def->fields[i].nullable_action =
+				ON_CONFLICT_ACTION_NONE;
+			p->def->fields[i].is_nullable = true;
+		} else if (p->iPKey == (int)i &&
+			    p->def->fields[i].nullable_action ==
+			    ON_CONFLICT_ACTION_NONE) {
+			/*
+			 * PRIMARY KEY can not be defined with
+			 * ON_CONFLICT_ACTION_NONE.
+			 */
+			const char *err_str =
+				tt_sprintf("Cannot define PRIMARY KEY "
+					   "constraint on nullable column in "
+					   "table '%s'", p->def->name);
+			diag_set(ClientError, ER_SQL, err_str);
+			pParse->rc = SQL_TARANTOOL_ERROR;
+			pParse->nErr++;
+			return;
+		}
+	}
+
 	if (!p->def->opts.is_view) {
 		if ((p->tabFlags & TF_HasPrimaryKey) == 0) {
 			sqlite3ErrorMsg(pParse,
diff --git a/src/box/sql/parse.y b/src/box/sql/parse.y
index ac935fd..6463019 100644
--- a/src/box/sql/parse.y
+++ b/src/box/sql/parse.y
@@ -276,7 +276,7 @@ ccons ::= DEFAULT id(X).              {
 // In addition to the type name, we also care about the primary key and
 // UNIQUE constraints.
 //
-ccons ::= NULL onconf.
+ccons ::= NULL onconf.           {sqlite3AddNotNull(pParse, ON_CONFLICT_ACTION_NONE);}
 ccons ::= NOT NULL onconf(R).    {sqlite3AddNotNull(pParse, R);}
 ccons ::= PRIMARY KEY sortorder(Z) onconf(R) autoinc(I).
                                  {sqlite3AddPrimaryKey(pParse,0,R,I,Z);}
diff --git a/test/sql/on-conflict.result b/test/sql/on-conflict.result
index c0d0de0..bdc2c76 100644
--- a/test/sql/on-conflict.result
+++ b/test/sql/on-conflict.result
@@ -99,3 +99,16 @@ box.sql.execute('DROP TABLE t1')
 box.sql.execute('DROP TABLE t2')
 ---
 ...
+--
+-- gh-3473: Primary key can be declared with NULL.
+--
+box.sql.execute('CREATE TABLE te17 (s1 INT NULL PRIMARY KEY NOT NULL);')
+---
+- error: 'SQL error: NULL declaration for column ''S1'' of table ''TE17'' has been
+    already set to ''none'''
+...
+box.sql.execute('CREATE TABLE te17 (s1 INT NULL PRIMARY KEY);')
+---
+- error: 'SQL error: Cannot define PRIMARY KEY constraint on nullable column in table
+    ''TE17'''
+...
diff --git a/test/sql/on-conflict.test.lua b/test/sql/on-conflict.test.lua
index b6d92f7..94eb84f 100644
--- a/test/sql/on-conflict.test.lua
+++ b/test/sql/on-conflict.test.lua
@@ -38,3 +38,9 @@ box.sql.execute('DROP TABLE p')
 box.sql.execute('DROP TABLE e')
 box.sql.execute('DROP TABLE t1')
 box.sql.execute('DROP TABLE t2')
+
+--
+-- gh-3473: Primary key can be declared with NULL.
+--
+box.sql.execute('CREATE TABLE te17 (s1 INT NULL PRIMARY KEY NOT NULL);')
+box.sql.execute('CREATE TABLE te17 (s1 INT NULL PRIMARY KEY);')
-- 
2.7.4