Add Magnet Link by Hash Only #1090

Added the possiblity of add a magnet only by the hash.

main.pas

@@ -945,6 +945,21 @@ function WndCallback(Ahwnd: HWND; uMsg: UINT; wParam: WParam; lParam: LParam):LR
 
   {$endif windows}
 
+  function IsHash(Hash: String): boolean;
+  var i: integer;
+  begin
+        if Hash = '' then exit;
+        if Length(Hash) = 32 then   // possible base32 encoded hash
+                        try
+                           Hash:=StrToHex(Base32Decode(UpperCase(Hash)));
+                        except
+                           exit;
+                        end;
+       if Length(Hash) <> 40 then exit;
+       Result := true;
+       for i := 1 to 40 do if not (Hash[i] in ['a' .. 'f', 'A'..'F', '0'..'9']) then Result := false;
+  end;
+
 procedure TMainForm.ReadLocalFolderWatch;
 var
   sr: TSearchRec;
@@ -2213,7 +2228,10 @@ procedure TMainForm.acAddLinkExecute(Sender: TObject);
   try
     AppNormal;
     if ShowModal = mrOk then
-      DoAddTorrent(edLink.Text);
+      begin
+           if isHash(edLink.Text) then edLink.Text := 'magnet:?xt=urn:btih:'+ edLink.Text;
+           DoAddTorrent(edLink.Text);
+      end;
   finally
     Free;
   end;
@@ -7608,6 +7626,7 @@ procedure TMainForm.CheckClipboardLink;
     if s = FLastClipboardLink then
       exit;
     FLastClipboardLink:=s;
+    if isHash(s) then s := 'magnet:?xt=urn:btih:' + s;
     if not IsProtocolSupported(s) then
       exit;
     if (Pos('magnet:', LazUTF8.UTF8LowerCase(s)) <> 1) and (LazUTF8.UTF8LowerCase(Copy(s, Length(s) - Length(strTorrentExt) + 1, MaxInt)) <> strTorrentExt) then