driver: set libc environment in init

modernc.org/libc.Start does this when wrapping funcs main to seed data
for libc.Xgetenv and friends.

However, sqlite doesn't use libc.Start. It sets libc bits up in an
init func. This leaves the libc view of the enivorment empty/null.

When the sqlite "localtime" modifier used with datetime/strftime/etc,
sqlite eventually calls libc.Xlocaltime which wants to read TZ from
the environment. With an empty/null libc enivornment, this segfaults.

To fix that, call libc.SetEnviron in func init like libc.Start
does.

Fixes https://gitlab.com/cznic/sqlite/-/issues/49

all_test.go

@@ -1178,6 +1178,19 @@ func TestTimeScan(t *testing.T) {
 	}
 }
 
+// https://gitlab.com/cznic/sqlite/-/issues/49
+func TestTimeLocaltime(t *testing.T) {
+	db, err := sql.Open(driverName, "file::memory:")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer db.Close()
+
+	if _, err := db.Exec("select datetime('now', 'localtime')"); err != nil {
+		t.Fatal(err)
+	}
+}
+
 // https://sqlite.org/lang_expr.html#varparam
 // https://gitlab.com/cznic/sqlite/-/issues/42
 func TestBinding(t *testing.T) {

sqlite.go

@@ -14,6 +14,7 @@ import (
 	"fmt"
 	"io"
 	"math"
+	"os"
 	"reflect"
 	"runtime"
 	"strconv"
@@ -119,6 +120,9 @@ var (
 
 func init() {
 	tls := libc.NewTLS()
+
+	libc.SetEnviron(tls, os.Environ())
+
 	if sqlite3.Xsqlite3_threadsafe(tls) == 0 {
 		panic(fmt.Errorf("sqlite: thread safety configuration error"))
 	}