Disable double-quoted string literals

CHANGELOG.md

@@ -29,6 +29,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Properly clean up WAL when using `sqlitex.Pool`
   ([#14](https://github.com/zombiezen/go-sqlite/issues/14))
+- Disabled double-quoted string literals.
 
 ## [0.5.0][] - 2021-05-22
 

sqlite.go

@@ -82,6 +82,36 @@ func OpenConn(path string, flags ...OpenFlags) (*Conn, error) {
 		return nil, err
 	}
 
+	// Disable double-quoted string literals.
+	varArgs := libc.Xmalloc(c.tls, ptrSize)
+	if varArgs == 0 {
+		c.Close()
+		return nil, fmt.Errorf("sqlite: open %q: cannot allocate memory", path)
+	}
+	defer libc.Xfree(c.tls, varArgs)
+	res := ResultCode(lib.Xsqlite3_db_config(
+		c.tls,
+		c.conn,
+		lib.SQLITE_DBCONFIG_DQS_DDL,
+		libc.VaList(varArgs, int32(0), uintptr(0)),
+	))
+	if err := reserr(res); err != nil {
+		// Making error opaque because it's not part of the primary connection
+		// opening and reflects an internal error.
+		return nil, fmt.Errorf("sqlite: open %q: disable double-quoted string literals: %v", path, err)
+	}
+	res = ResultCode(lib.Xsqlite3_db_config(
+		c.tls,
+		c.conn,
+		lib.SQLITE_DBCONFIG_DQS_DML,
+		libc.VaList(varArgs, int32(0), uintptr(0)),
+	))
+	if err := reserr(res); err != nil {
+		// Making error opaque because it's not part of the primary connection
+		// opening and reflects an internal error.
+		return nil, fmt.Errorf("sqlite: open %q: disable double-quoted string literals: %v", path, err)
+	}
+
 	if openFlags&OpenWAL != 0 {
 		stmt, _, err := c.PrepareTransient("PRAGMA journal_mode=wal;")
 		if err != nil {

sqlite_test.go

@@ -123,6 +123,16 @@ func TestConn(t *testing.T) {
 	if !reflect.DeepEqual(wantInts, gotInts) {
 		t.Errorf("SELECT foo2: got %v, want %v", gotInts, wantInts)
 	}
+
+	if err := stmt.Finalize(); err != nil {
+		t.Error(err)
+	}
+
+	stmt, err = c.Prepare(`SELECT "foo" = 'foo';`)
+	if err == nil {
+		stmt.Finalize()
+		t.Error("Double-quoted string literals are permitted")
+	}
 }
 
 func TestEarlyInterrupt(t *testing.T) {