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avoid error for calls to functions returning varargout that ignore final outputs (bug #36221) * pt-assign.cc (tree_multi_assignment::rvalue): Don't error if more output values are requested than returned when the requested outputs are ignored. New test.
author John W. Eaton <jwe@octave.org>
date Thu, 19 Apr 2012 16:24:14 -0400
parents 72c96de7a403
children
line wrap: on
line diff
--- a/src/pt-assign.cc
+++ b/src/pt-assign.cc
@@ -431,7 +431,30 @@
                     }
                 }
               else
-                error ("element number %d undefined in return list", k+1);
+                {
+                  // This can happen for a function like
+                  //
+                  //   function varargout = f ()
+                  //     varargout{1} = nargout;
+                  //   endfunction
+                  //
+                  // called with
+                  //
+                  //    [a, ~] = f ();
+                  //
+                  // Then the list of of RHS values will contain one
+                  // element but we are iterating over the list of all
+                  // RHS values.  We shouldn't complain that a value we
+                  // don't need is missing from the list.
+
+                  if (ult.is_black_hole ())
+                    {
+                      k++;
+                      continue;
+                    }
+                  else
+                    error ("element number %d undefined in return list", k+1);
+                }
             }
 
           if (error_state)
@@ -467,6 +490,19 @@
   return retval;
 }
 
+/*
+%!function varargout = f ()
+%!  varargout{1} = nargout;
+%!endfunction
+%!
+%!test
+%! [a, ~] = f ();
+%! assert (a, 2);
+%!test
+%! [a, ~, ~, ~, ~] = f ();
+%! assert (a, 5);
+*/
+
 std::string
 tree_multi_assignment::oper (void) const
 {