More consistent interrupts.

blob.go

@@ -253,6 +253,7 @@ func (b *Blob) Seek(offset int64, whence int) (int64, error) {
 //
 // https://sqlite.org/c3ref/blob_reopen.html
 func (b *Blob) Reopen(row int64) error {
+	b.c.checkInterrupt(b.c.handle)
 	err := b.c.error(b.c.call("sqlite3_blob_reopen", uint64(b.handle), uint64(row)))
 	b.bytes = int64(b.c.call("sqlite3_blob_bytes", uint64(b.handle)))
 	b.offset = 0

conn.go

@@ -204,6 +204,7 @@ func (c *Conn) PrepareFlags(sql string, flags PrepareFlag) (stmt *Stmt, tail str
 	tailPtr := c.arena.new(ptrlen)
 	sqlPtr := c.arena.string(sql)
 
+	c.checkInterrupt(c.handle)
 	r := c.call("sqlite3_prepare_v3", uint64(c.handle),
 		uint64(sqlPtr), uint64(len(sql)+1), uint64(flags),
 		uint64(stmtPtr), uint64(tailPtr))

tests/conn_test.go

@@ -7,6 +7,7 @@ import (
 	"path/filepath"
 	"strings"
 	"testing"
+	"time"
 
 	"github.com/ncruces/go-sqlite3"
 	_ "github.com/ncruces/go-sqlite3/embed"
@@ -148,7 +149,10 @@ func TestConn_SetInterrupt(t *testing.T) {
 	defer stmt.Close()
 
 	db.SetInterrupt(ctx)
-	go cancel()
+	go func() {
+		time.Sleep(time.Millisecond)
+		cancel()
+	}()
 
 	// Interrupting works.
 	err = stmt.Exec()