Fix literalPacket.getText()

We now close streams after reading them, so we can no longer use
stream.locked for a proxy for "has been read". What we want is the
internal [[disturbed]] property, but we can't access it for native
streams.

Since we always read the stream when calling getText(), it's not
an issue.

src/packet/literal.js

@@ -62,7 +62,7 @@ Literal.prototype.setText = function(text, format='utf8') {
  * @returns {String} literal data as text
  */
 Literal.prototype.getText = function(clone=false) {
-  if (this.text === null || this.text.locked) {
+  if (this.text === null || util.isStream(this.text)) { // Assume that this.text has been read
     let lastChar = '';
     const decoder = new TextDecoder('utf8');
     // eslint-disable-next-line no-inner-declarations

src/packet/signature.js

@@ -710,6 +710,7 @@ Signature.prototype.verify = async function (key, data) {
     const endian = publicKeyAlgorithm === enums.publicKey.eddsa ? 'le' : 'be';
     const mpi = [];
     let i = 0;
+    this.signature = await stream.readToEnd(this.signature);
     for (let j = 0; j < mpicount; j++) {
       mpi[j] = new type_mpi();
       i += mpi[j].read(this.signature.subarray(i, this.signature.length), endian);