Fixes IndySockets#471

Lib/Protocols/IdReplyPOP3.pas

@@ -239,6 +239,8 @@ class function TIdReplyPOP3.FindCodeTextDelim(const AText: String): Integer;
   //we do things this way because a line can start with a minus as in
   //-ERR [IN-USE] Mail box in use
   LBuf := AText;
+  // TODO: use PosEx() instead, then we can just skip
+  // past the '-' without physically removing it...
   if TextStartsWith(LBuf, '-') then begin
     Delete(LBuf, 1, 1);
     LAddBackFlag := True;
@@ -323,7 +325,7 @@ class function TIdReplyPOP3.IsValidEnhancedCode(const AText : String; const AStr
         if AStrict then begin
           Result := PosInStrArray(LBuf, VALID_ENH_CODES) > -1;
         end else begin
-          {We don't use PosInStrArray because we only want the fist
+          {We don't use PosInStrArray because we only want the first
           charactors in our string to match.  This is necessary because
           the POP3 enhanced codes will be hierarchical as time goes on.
           }
@@ -372,10 +374,19 @@ procedure TIdReplyPOP3.SetFormattedReply(const AValue: TStrings);
   i: Integer;
   idx : Integer;
   LOrd : Integer;
-  LBuf : String;
+  LBuf, LEnh : String;
+  LText : TStringList;
 begin
   Clear;
   if AValue.Count > 0 then begin
+    // RLebeau: what is the purpose of this ExtractTextPosArray() shenanigans? Why
+    // are we allowing the status code to appear outside of the 1st line? That does
+    // not conform to the POP3 protocol spec. Are any servers actually doing this
+    // in practice? None of the other TIdReply classes handle this possibility...
+    //
+    // Note: Microsoft's Outlook365 POP3 server DOES send a greeting WITHOUT a
+    // status code if a client connects using implicit TLS 1.0 or 1.1!  That was
+    // apparently allowed by RFC 1725, but not anymore by RFC 1939!
     LOrd := ExtractTextPosArray(AValue[0]);
     if LOrd > -1 then begin
       Code := VALID_POP3_STR[LOrd];
@@ -395,7 +406,20 @@ procedure TIdReplyPOP3.SetFormattedReply(const AValue: TStrings);
       Text.Add(LBuf);
     end;
     if LOrd = -1 then begin
-      Code := ST_ERR;
+      // RLebeau 4/30/2023: warning - TIdReply.SetCode() calls Clear(),
+      // which will LOSE any EnhancedCode and Text values already assigned
+      // above!  We need to preserve them here. This wouldn't be an issue
+      // anymore if we get rid of the ExtractTextPosArray() nonsense above...
+      LText := TStringList.Create;
+      try
+        LText.Assign(Text);
+        LEnh := FEnhancedCode;
+        Code := ST_ERR;
+        Text.Assign(LText);
+        FEnhancedCode := LEnh;
+      finally
+        LText.Free;
+      end;
     end;
   end;
 end;