From f789c2fb8b8c2194c400cef1b8ffeec9f2e0b14f Mon Sep 17 00:00:00 2001
From: Nuno Cruces <ncruces@users.noreply.github.com>
Date: Thu, 16 Mar 2023 12:27:44 +0000
Subject: [PATCH] OPEN_NOFOLLOW.

---
 backup.go          |  2 +-
 conn.go            |  8 ++++++--
 const.go           |  2 ++
 driver/driver.go   |  2 +-
 tests/conn_test.go |  2 +-
 vfs.go             | 14 +++++++++++---
 6 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/backup.go b/backup.go
index c931347..fe726f2 100644
--- a/backup.go
+++ b/backup.go
@@ -33,7 +33,7 @@ func (src *Conn) Backup(srcDB, dstURI string) error {
 //
 // https://www.sqlite.org/backup.html
 func (dst *Conn) Restore(dstDB, srcURI string) error {
-	src, err := dst.openDB(srcURI, OPEN_READWRITE|OPEN_CREATE|OPEN_URI)
+	src, err := dst.openDB(srcURI, OPEN_READONLY|OPEN_URI)
 	if err != nil {
 		return err
 	}
diff --git a/conn.go b/conn.go
index 43ae40d..8c8ed3b 100644
--- a/conn.go
+++ b/conn.go
@@ -26,19 +26,23 @@ type Conn struct {
 	pending   *Stmt
 }
 
-// Open calls [OpenFlags] with [OPEN_READWRITE], [OPEN_CREATE] and [OPEN_URI].
+// Open calls [OpenFlags] with [OPEN_READWRITE], [OPEN_CREATE], [OPEN_URI] and [OPEN_NOFOLLOW].
 func Open(filename string) (*Conn, error) {
-	return newConn(filename, OPEN_READWRITE|OPEN_CREATE|OPEN_URI)
+	return newConn(filename, OPEN_READWRITE|OPEN_CREATE|OPEN_URI|OPEN_NOFOLLOW)
 }
 
 // OpenFlags opens an SQLite database file as specified by the filename argument.
 //
+// If none of the required flags is used, a combination of [OPEN_READWRITE] and [OPEN_CREATE] is used.
 // If a URI filename is used, PRAGMA statements to execute can be specified using "_pragma":
 //
 //	sqlite3.Open("file:demo.db?_pragma=busy_timeout(10000)&_pragma=locking_mode(normal)")
 //
 // https://www.sqlite.org/c3ref/open.html
 func OpenFlags(filename string, flags OpenFlag) (*Conn, error) {
+	if flags&(OPEN_READONLY|OPEN_READWRITE|OPEN_CREATE) == 0 {
+		flags |= OPEN_READWRITE | OPEN_CREATE
+	}
 	return newConn(filename, flags)
 }
 
diff --git a/const.go b/const.go
index 94497bc..b2fb261 100644
--- a/const.go
+++ b/const.go
@@ -7,6 +7,8 @@ const (
 	_ROW  = 100 /* sqlite3_step() has another row ready */
 	_DONE = 101 /* sqlite3_step() has finished executing */
 
+	_OK_SYMLINK = (_OK | (2 << 8)) /* internal use only */
+
 	_UTF8 = 1
 
 	_MAX_STRING   = 512 // Used for short strings: names, error messages…
diff --git a/driver/driver.go b/driver/driver.go
index 06dc4df..be551de 100644
--- a/driver/driver.go
+++ b/driver/driver.go
@@ -44,7 +44,7 @@ func init() {
 type sqlite struct{}
 
 func (sqlite) Open(name string) (_ driver.Conn, err error) {
-	c, err := sqlite3.OpenFlags(name, sqlite3.OPEN_READWRITE|sqlite3.OPEN_CREATE|sqlite3.OPEN_URI|sqlite3.OPEN_EXRESCODE)
+	c, err := sqlite3.Open(name)
 	if err != nil {
 		return nil, err
 	}
diff --git a/tests/conn_test.go b/tests/conn_test.go
index 57ed67b..a5baf1a 100644
--- a/tests/conn_test.go
+++ b/tests/conn_test.go
@@ -13,7 +13,7 @@ import (
 func TestConn_Open_dir(t *testing.T) {
 	t.Parallel()
 
-	_, err := sqlite3.Open(".")
+	_, err := sqlite3.OpenFlags(".", 0)
 	if err == nil {
 		t.Fatal("want error")
 	}
diff --git a/vfs.go b/vfs.go
index bd2228a..9bd9913 100644
--- a/vfs.go
+++ b/vfs.go
@@ -143,7 +143,7 @@ func vfsFullPathname(ctx context.Context, mod api.Module, pVfs, zRelative, nFull
 	rel := memory{mod}.readString(zRelative, _MAX_PATHNAME)
 	abs, err := filepath.Abs(rel)
 	if err != nil {
-		return uint32(IOERR)
+		return uint32(CANTOPEN_FULLPATH)
 	}
 
 	// Consider either using [filepath.EvalSymlinks] to canonicalize the path (as the Unix VFS does).
@@ -155,10 +155,18 @@ func vfsFullPathname(ctx context.Context, mod api.Module, pVfs, zRelative, nFull
 		return uint32(CANTOPEN_FULLPATH)
 	}
 	mem := memory{mod}.view(zFull, size)
-
 	mem[len(abs)] = 0
 	copy(mem, abs)
-	return _OK
+
+	if fi, err := os.Lstat(abs); err == nil {
+		if fi.Mode()&fs.ModeSymlink != 0 {
+			return _OK_SYMLINK
+		}
+		return _OK
+	} else if errors.Is(err, fs.ErrNotExist) {
+		return _OK
+	}
+	return uint32(CANTOPEN_FULLPATH)
 }
 
 func vfsDelete(ctx context.Context, mod api.Module, pVfs, zPath, syncDir uint32) uint32 {