fix detection of multi-statements in ComPrepare

go/mysql/conn.go

@@ -1105,32 +1105,47 @@ func (c *Conn) handleNextCommand(ctx context.Context, handler Handler) error {
 			return nil
 		}
 
-		// Populate PrepareData
-		c.StatementID++
-		prepare := &PrepareData{
-			StatementID: c.StatementID,
-			PrepareStmt: query,
-		}
-
 		var err error
 		var statement sqlparser.Statement
-		var remainder string
-
 		parserOptions, err := handler.ParserOptionsForConnection(c)
 		if err != nil {
 			log.Errorf("unable to determine parser options for current connection: %s", err.Error())
 			return err
 		}
 
+		var queries []string
 		if !c.DisableClientMultiStatements && c.Capabilities&CapabilityClientMultiStatements != 0 {
-			var ri int
-			statement, ri, err = sqlparser.ParseOneWithOptions(ctx, query, parserOptions)
-			if ri < len(query) {
-				remainder = query[ri:]
+			queries, err = sqlparser.SplitStatementToPieces(query)
+			if err != nil {
+				log.Errorf("error splitting query: %v", c, err)
+				if werr := c.writeErrorPacketFromError(err); werr != nil {
+					// If we can't even write the error, we're done.
+					log.Errorf("Error writing query error to %s: %v", c, werr)
+					return werr
+				}
+				return nil
+			}
+			if len(queries) != 1 {
+				err := fmt.Errorf("cannot prepare multiple statements")
+				if werr := c.writeErrorPacketFromError(err); werr != nil {
+					// If we can't even write the error, we're done.
+					log.Errorf("Error writing query error to %s: %v", c, werr)
+					return werr
+				}
+				return nil
 			}
 		} else {
-			statement, err = sqlparser.ParseWithOptions(ctx, query, parserOptions)
+			queries = []string{query}
 		}
+
+		// Populate PrepareData
+		c.StatementID++
+		prepare := &PrepareData{
+			StatementID: c.StatementID,
+			PrepareStmt: queries[0],
+		}
+
+		statement, err = sqlparser.ParseWithOptions(ctx, query, parserOptions)
 		if err != nil {
 			log.Errorf("Error while parsing prepared statement: %s", err.Error())
 			if werr := c.writeErrorPacketFromError(err); werr != nil {
@@ -1140,15 +1155,6 @@ func (c *Conn) handleNextCommand(ctx context.Context, handler Handler) error {
 			}
 			return nil
 		}
-		if remainder != "" {
-			err := fmt.Errorf("can not prepare multiple statements")
-			if werr := c.writeErrorPacketFromError(err); werr != nil {
-				// If we can't even write the error, we're done.
-				log.Errorf("Error writing query error to %s: %v", c, werr)
-				return werr
-			}
-			return nil
-		}
 
 		// Walk the parsed statement tree and find any SQLVal nodes that are parameterized.
 		paramsCount := uint16(0)

go/mysql/query_test.go

@@ -1114,3 +1114,69 @@ func TestExecuteQueries(t *testing.T) {
 		}
 	})
 }
+
+func TestComStmtPrepareWithTrailingNewLine (t *testing.T) {
+	listener, sConn, cConn := createSocketPair(t)
+	defer func() {
+		listener.Close()
+		sConn.Close()
+		cConn.Close()
+	}()
+
+	sql := "select ?;\n"
+	data := MockQueryPackets(t, sql)
+	if err := cConn.writePacket(data); err != nil {
+		t.Fatalf("writePacket failed: %v", err)
+	}
+
+	prepare, result := MockPrepareData(t)
+	sConn.PrepareData = make(map[uint32]*PrepareData)
+	sConn.PrepareData[prepare.StatementID] = prepare
+
+	sConn.Capabilities |= CapabilityClientMultiStatements
+	handler := &testHandler{
+		result: result,
+	}
+	err := sConn.handleNextCommand(context.Background(), handler)
+	if err != nil {
+		t.Fatalf("handleNextCommand failed: %v", err)
+	}
+
+	if err := cConn.ExecuteStreamFetch(sql); err != nil {
+		t.Fatalf("ExecuteStreamFetch(%v) failed: %v", sql, err)
+		return
+	}
+}
+
+func TestComStmtPrepareMultiStmt (t *testing.T) {
+	listener, sConn, cConn := createSocketPair(t)
+	defer func() {
+		listener.Close()
+		sConn.Close()
+		cConn.Close()
+	}()
+
+	sql := "select ?; select ?;"
+	data := MockQueryPackets(t, sql)
+	if err := cConn.writePacket(data); err != nil {
+		t.Fatalf("writePacket failed: %v", err)
+	}
+
+	prepare, result := MockPrepareData(t)
+	sConn.PrepareData = make(map[uint32]*PrepareData)
+	sConn.PrepareData[prepare.StatementID] = prepare
+
+	sConn.Capabilities |= CapabilityClientMultiStatements
+	handler := &testHandler{
+		result: result,
+	}
+	err := sConn.handleNextCommand(context.Background(), handler)
+	if err != nil {
+		t.Fatalf("handleNextCommand failed: %v", err)
+	}
+
+	if err := cConn.ExecuteStreamFetch(sql); err == nil {
+		t.Fatalf("expected error, but received nil")
+		return
+	}
+}