panic index out of range inserting empty []byte in BLOB column

[xhit]

• os Version: Windows 10
• cli-driver Version: 11.1
• Db2 Server Version: 11.5.0.1077
• go Version: 1.13.5

go env Output:

$ go env
set GO111MODULE=
set GOARCH=amd64
set GOBIN=
set GOCACHE=C:\Users\sdelacruz\AppData\Local\go-build
set GOENV=C:\Users\sdelacruz\AppData\Roaming\go\env
set GOEXE=.exe
set GOFLAGS=
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GONOPROXY=
set GONOSUMDB=
set GOOS=windows
set GOPATH=C:\Users\sdelacruz\Documents\go
set GOPRIVATE=
set GOPROXY=https://proxy.golang.org,direct
set GOROOT=c:\go
set GOSUMDB=sum.golang.org
set GOTMPDIR=
set GOTOOLDIR=c:\go\pkg\tool\windows_amd64
set GCCGO=gccgo
set AR=ar
set CC=gcc
set CXX=g++
set CGO_ENABLED=1
set GOMOD=C:\Users\sdelacruz\Documents\go\src\sdi\go.mod
set CGO_CFLAGS=-g -O2
set CGO_CPPFLAGS=
set CGO_CXXFLAGS=-g -O2
set CGO_FFLAGS=-g -O2
set CGO_LDFLAGS=-g -O2
set PKG_CONFIG=pkg-config
set GOGCCFLAGS=-m64 -mthreads -fmessage-length=0 -fdebug-prefix-map=C:\Users\SDELAC~1\AppData\Local\Temp\go-build670067514=/tmp/go-build -gno-record-gcc-switches

The driver cannot insert nil in a column with data type BLOB, launch this error from IBM:
SQLExecute: {HY099} [IBM][CLI Driver] CLI0164E Nullable type out of range. SQLSTATE=HY099

So trying to insert a empty []byte in a data type BLOB return this panic:

panic: runtime error: index out of range [0] with length 0

goroutine 18 [running]:
github.com/ibmdb/go_ibm_db.(*Parameter).BindValue(0xc0000940d8, 0x10001, 0x3, 0xcba240, 0xc00029a240, 0x0, 0x0)
        C:/Users/sdelacruz/Documents/go/pkg/mod/github.com/ibmdb/go_ibm_db@v0.2.0/param.go:126 +0x17a8
github.com/ibmdb/go_ibm_db.(*ODBCStmt).Exec(0xc00225e410, 0xc000322640, 0x14, 0x14, 0x14, 0x14)
        C:/Users/sdelacruz/Documents/go/pkg/mod/github.com/ibmdb/go_ibm_db@v0.2.0/odbcstmt.go:107 +0x94c
github.com/ibmdb/go_ibm_db.(*Stmt).Exec(0xc000298000, 0xc000322640, 0x14, 0x14, 0x0, 0x0, 0x0, 0x0)
        C:/Users/sdelacruz/Documents/go/pkg/mod/github.com/ibmdb/go_ibm_db@v0.2.0/stmt.go:66 +0xf0
database/sql.ctxDriverStmtExec(0xee74c0, 0xc000020108, 0xee8100, 0xc000298000, 0xc000017500, 0x14, 0x14, 0x14, 0x14, 0x0, ...)
        c:/go/src/database/sql/ctxutil.go:77 +0x16c
database/sql.resultFromStatement(0xee74c0, 0xc000020108, 0xee55c0, 0xc00029d3e0, 0xc00002c040, 0xc000322140, 0x14, 0x14, 0x0, 0x0, ...)
        c:/go/src/database/sql/sql.go:2435 +0x15d
database/sql.(*Stmt).ExecContext(0xc000318000, 0xee74c0, 0xc000020108, 0xc000322140, 0x14, 0x14, 0x0, 0x0, 0x0, 0x0)
        c:/go/src/database/sql/sql.go:2411 +0x200
        c:/go/src/database/sql/sql.go:2423
...
exit status 2

[akhilravuri1]

Hi @xhit
please provide a sample program to reproduce the error?
Is that column accepts null data?
Thanks,
Akhil

[xhit]

A BLOB column can accept NULL but with this driver trigger an error but that is another issue. See #80.

This issue is about insert an empty []byte and PR #74 fix this.

To reproduce:

package main

import (
	"database/sql"
	"fmt"

	_ "github.com/ibmdb/go_ibm_db"
)

func main() {
	//connecto to DB
	db, err := connectDB2("localhost", "SAMPLE", "SCHEMATEST", "db2admin", "pass", 50000)
	if err != nil {
		panic(err)
	}

	defer db.Close()

	queryDrop := `drop table "issue73";`

	db.Exec(queryDrop)

	queryCreate := `CREATE TABLE "issue73" ("blob_column" BLOB(50));`

	_, err = db.Exec(queryCreate)
	if err != nil {
		panic(err)
	}

	defer db.Exec(queryDrop)

	queryInsert := `insert into "issue73" ("blob_column") values (?);‪`

	//inserting a empty []byte panic with error panic: runtime error: index out of range [0] with length 0
	_, err = db.Exec(queryInsert, []byte{})
	if err != nil {
		panic(err)
	}
}

//connect to db2 database
func connectDB2(host, database, schema, user, password string, port int) (*sql.DB, error) {

	//Password cannot contains ;
	connString := fmt.Sprintf("HOSTNAME=%s;DATABASE=%s;PORT=%d;UID=%s;PWD=%s", host, database, port, user, password)

	db, err := sql.Open("go_ibm_db", connString)

	if err != nil {
		return nil, err
	}

	err = db.Ping()

	if err != nil {
		return nil, err
	}

	db.SetMaxOpenConns(1)
	db.SetMaxIdleConns(1)

	//set the schema
	if len(schema) > 0 {
		_, err = db.Exec("SET CURRENT SCHEMA ?", schema)

		if err != nil {
			return nil, err
		}
	}

	return db, nil
}

[xhit]

Hi @akhilravuri1, can you check this panic?

Thanks.

[akhilravuri1]

Hi @xhit
I have checked this panic. Your pull req also passes all the test cases.
We are planning to release a new version. I will add your fix in that version.

Thanks,
Akhil