use QScintilla instead of QTextEdit for new terminal widget * command-widget.cc (ctor): pass qobj to console; (insert_interpreter_output): just append output message to console text; (console::console): initialize QScintilla, remove obsolete document; (console::new_command_line): append new line, add prompt, remember current cursor pos for later use, append possibly given command string; (console::accept_command_line): just get last line, and append a new line; (console::append_block): removed; (console::append_string): new function appending a string and moving cursor to the end; (console::keyPressEvent): process QsciScintilla::keyPressEvent * command-widget.h: include Qsci/qsciscintilla.h, console inherits from QsciScintilla and gets oct_qobj for later use, new function append_string, new class variable m_command_position for storing the begin of the active command line

%!function out = bug54490 ()
%!  global k;
%!  k = 1;
%!  out = 3;
%!endfunction

%!test <*54490>
%! global k;
%! k = 2;
%! a = [5, 6];
%! a(k) = bug54490 ();
%! assert (a, [5, 3]);
%! k = 2;
%! a = [5, 6];
%! [a(k)] = bug54490 ();
%! assert (a, [5, 3]);
%! clear -global k;  # cleanup after test