Replace ConnError/StmtError pointer by simple value.

.travis.yml

 language: go
 go:
-  - 1.1
   - tip
 before_install:
  - echo "yes" | sudo add-apt-repository ppa:travis-ci/sqlite3

busy_test.go

@@ -31,7 +31,7 @@ func TestInterrupt(t *testing.T) {
 		t.Fatalf("got %v; want interrupt", err)
 	}
 	//println(err.Error())
-	if se, ok := err.(*StmtError); !ok || se.Code() != ErrInterrupt {
+	if se, ok := err.(StmtError); !ok || se.Code() != ErrInterrupt {
 		t.Errorf("got %#v; want interrupt", err)
 	}
 }
@@ -58,7 +58,7 @@ func TestDefaultBusy(t *testing.T) {
 	if err == nil {
 		t.Fatalf("got %v; want lock", err)
 	}
-	if se, ok := err.(*StmtError); !ok || se.Code() != ErrBusy {
+	if se, ok := err.(StmtError); !ok || se.Code() != ErrBusy {
 		t.Fatalf("got %#v; want lock", err)
 	}
 }

driver.go

@@ -86,7 +86,7 @@ func (d *impl) Open(name string) (driver.Conn, error) {
 // Unwrap gives access to underlying driver connection.
 func Unwrap(db *sql.DB) *Conn {
 	_, err := db.Exec("unwrap")
-	if cerr, ok := err.(*ConnError); ok {
+	if cerr, ok := err.(ConnError); ok {
 		return cerr.c
 	}
 	return nil
@@ -99,6 +99,9 @@ func (c *conn) Exec(query string, args []driver.Value) (driver.Result, error) {
 		return nil, driver.ErrBadConn
 	}
 	if len(args) == 0 {
+		if query == "unwrap" {
+			return nil, ConnError{c: c.c}
+		}
 		if err := c.c.FastExec(query); err != nil {
 			return nil, err
 		}

sqlite.go

@@ -32,23 +32,23 @@ type ConnError struct {
 }
 
 // Code returns the original SQLite error code (or -1 for errors generated by the Go wrapper)
-func (e *ConnError) Code() Errno {
+func (e ConnError) Code() Errno {
 	return e.code
 }
 
 // ExtendedCode returns the SQLite extended error code.
 // (See http://www.sqlite.org/c3ref/errcode.html)
 // FIXME it might be the case that a second error occurs on a separate thread in between the time of the first error and the call to this method.
-func (e *ConnError) ExtendedCode() int {
+func (e ConnError) ExtendedCode() int {
 	return int(C.sqlite3_extended_errcode(e.c.db))
 }
 
 // Filename returns database file name from which the error comes from.
-func (e *ConnError) Filename() string {
+func (e ConnError) Filename() string {
 	return e.c.Filename("main")
 }
 
-func (e *ConnError) Error() string { // FIXME code.Error() & e.msg are often redundant...
+func (e ConnError) Error() string { // FIXME code.Error() & e.msg are often redundant...
 	if len(e.details) > 0 {
 		return fmt.Sprintf("%s (%s) (%s)", e.msg, e.details, e.code.Error())
 	} else if len(e.msg) > 0 {
@@ -115,7 +115,7 @@ func (c *Conn) error(rv C.int, details ...string) error {
 	if rv == C.SQLITE_OK {
 		return nil
 	}
-	err := &ConnError{c: c, code: Errno(rv), msg: C.GoString(C.sqlite3_errmsg(c.db))}
+	err := ConnError{c: c, code: Errno(rv), msg: C.GoString(C.sqlite3_errmsg(c.db))}
 	if len(details) > 0 {
 		err.details = details[0]
 	}
@@ -123,7 +123,7 @@ func (c *Conn) error(rv C.int, details ...string) error {
 }
 
 func (c *Conn) specificError(msg string, a ...interface{}) error {
-	return &ConnError{c: c, code: ErrSpecific, msg: fmt.Sprintf(msg, a...)}
+	return ConnError{c: c, code: ErrSpecific, msg: fmt.Sprintf(msg, a...)}
 }
 
 // LastError returns the error for the most recent failed sqlite3_* API call associated with a database connection.
@@ -136,7 +136,7 @@ func (c *Conn) LastError() error {
 	if errorCode == C.SQLITE_OK {
 		return nil
 	}
-	return &ConnError{c: c, code: Errno(errorCode), msg: C.GoString(C.sqlite3_errmsg(c.db))}
+	return ConnError{c: c, code: Errno(errorCode), msg: C.GoString(C.sqlite3_errmsg(c.db))}
 }
 
 // Conn represents a database connection handle.

sqlite_test.go

@@ -193,7 +193,7 @@ func TestConnExecWithSelect(t *testing.T) {
 
 	err := db.Exec("SELECT 1")
 	assert.T(t, err != nil, "error expected")
-	if serr, ok := err.(*StmtError); ok {
+	if serr, ok := err.(StmtError); ok {
 		assert.Equal(t, ErrSpecific, serr.Code())
 	} else {
 		t.Errorf("got %s; want StmtError", reflect.TypeOf(err))
@@ -270,7 +270,7 @@ func TestCommitMisuse(t *testing.T) {
 
 	err := db.Commit()
 	assert.T(t, err != nil, "error expected")
-	if cerr, ok := err.(*ConnError); ok {
+	if cerr, ok := err.(ConnError); ok {
 		assert.Equal(t, ErrError, cerr.Code())
 		assert.Equal(t, 1, cerr.ExtendedCode())
 	} else {

stmt.go

@@ -48,7 +48,7 @@ type StmtError struct {
 }
 
 // SQL returns the SQL associated with the prepared statement in error.
-func (e *StmtError) SQL() string {
+func (e StmtError) SQL() string {
 	return e.s.SQL()
 }
 
@@ -63,11 +63,11 @@ func (s *Stmt) error(rv C.int, details ...string) error {
 	if len(details) > 0 {
 		err.details = details[0]
 	}
-	return &StmtError{err, s}
+	return StmtError{err, s}
 }
 
 func (s *Stmt) specificError(msg string, a ...interface{}) error {
-	return &StmtError{ConnError{c: s.c, code: ErrSpecific, msg: fmt.Sprintf(msg, a...)}, s}
+	return StmtError{ConnError{c: s.c, code: ErrSpecific, msg: fmt.Sprintf(msg, a...)}, s}
 }
 
 // CheckTypeMismatch enables type check in Scan methods (default true)

stmt_test.go

@@ -176,7 +176,7 @@ func TestScanCheck(t *testing.T) {
 	assert.T(t, checkStep(t, s))
 	var i int
 	_, err = s.ScanByIndex(0, &i)
-	if serr, ok := err.(*StmtError); ok {
+	if serr, ok := err.(StmtError); ok {
 		assert.Equal(t, "", serr.Filename())
 		assert.Equal(t, ErrSpecific, serr.Code())
 		assert.Equal(t, s.SQL(), serr.SQL())
@@ -318,7 +318,6 @@ func TestStmtWithClosedDb(t *testing.T) {
 	s, err := db.Prepare("SELECT 1")
 	checkNoError(t, err, "prepare error: %s")
 	assert.Equal(t, db, s.Conn(), "conn")
-	defer s.Finalize()
 
 	err = db.Close()
 	checkNoError(t, err, "close error: %s")
@@ -339,7 +338,7 @@ func TestStmtExecWithSelect(t *testing.T) {
 	err = s.Exec()
 	assert.T(t, err != nil, "error expected")
 	//println(err.Error())
-	if serr, ok := err.(*StmtError); ok {
+	if serr, ok := err.(StmtError); ok {
 		assert.Equal(t, ErrSpecific, serr.Code())
 	} else {
 		t.Errorf("got %s; want StmtError", reflect.TypeOf(err))
@@ -384,7 +383,7 @@ func TestStmtSelectWithInsert(t *testing.T) {
 	exists, err := s.SelectOneRow()
 	assert.T(t, err != nil, "error expected")
 	//println(err.Error())
-	if serr, ok := err.(*StmtError); ok {
+	if serr, ok := err.(StmtError); ok {
 		assert.Equal(t, ErrSpecific, serr.Code())
 	} else {
 		t.Errorf("got %s; want StmtError", reflect.TypeOf(err))

trace.go

@@ -391,6 +391,8 @@ func ConfigLog(f Logger, udp interface{}) error {
 	return Errno(rv)
 }
 
+// ExplainQueryPlan outputs the corresponding EXPLAIN QUERY PLAN report to the specified writer
+// (See http://sqlite.org/eqp.html)
 func (s *Stmt) ExplainQueryPlan(w io.Writer) error {
 	sql := s.SQL()
 	if len(sql) == 0 {