# HG changeset patch
# User Fernando Alvarruiz <feralber@upvnet.upv.es>
# Date 1670470648 18000
# Node ID a18897e4c7b5dae4d75f31dace35d228c7dee4ff
# Parent  beb7f91a0a972a97c26d19a40d9bf8d3b038fd7a
classdef: call subsref method with correct nargout value (bug #48693)

* /libinterp/octave-value/ov-classdef.cc (octave_classdef::subsref): Correct
the nargout value for classdef subsref calls by checking the number of values
the indexing argument addresses, using the same code used by the non-classdef
subsref method.
* /test/bug-48693/bug-48693.tst, bug48693.m, module.mk: Add simple test
function files to verify subsref behavior.

diff -r beb7f91a0a97 -r a18897e4c7b5 libinterp/octave-value/ov-classdef.cc
--- a/libinterp/octave-value/ov-classdef.cc	Wed Dec 07 14:26:59 2022 +0100
+++ b/libinterp/octave-value/ov-classdef.cc	Wed Dec 07 22:37:28 2022 -0500
@@ -91,8 +91,29 @@
           count++;
           args(0) = octave_value (this);
 
+          // Attempt to set up a proper value for nargout at least in the
+          // simple case where the cs-list-type expression - i.e., {} or
+          // ().x, is the leading one.
+          bool maybe_cs_list_query = (type[0] == '.' || type[0] == '{'
+                                      || (type.length () > 1 && type[0] == '('
+                                          && type[1] == '.'));
+
+          if (maybe_cs_list_query)
+            {
+              // Set up a proper nargout for the subsref call by calling numel.
+              octave_value_list tmp;
+              if (type[0] != '.') tmp = idx.front ();
+              nargout = xnumel (tmp);
+            }
+
           retval = meth.execute (args, nargout, true, "subsref");
 
+          // Since we're handling subsref, if the list has more than one
+          // element, return it as a comma-separated list so that we can
+          // pass it to the evaluator
+          if (retval.length () > 1)
+            retval = octave_value (retval);
+
           return retval;
         }
     }
diff -r beb7f91a0a97 -r a18897e4c7b5 test/bug-48693/bug-48693.tst
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/bug-48693/bug-48693.tst	Wed Dec 07 22:37:28 2022 -0500
@@ -0,0 +1,3 @@
+%!test
+%! x = bug48693();
+%! assert ({x{1:10}}, num2cell (zeros(1,10)))
diff -r beb7f91a0a97 -r a18897e4c7b5 test/bug-48693/bug48693.m
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/bug-48693/bug48693.m	Wed Dec 07 22:37:28 2022 -0500
@@ -0,0 +1,7 @@
+classdef bug48693 < handle
+  methods
+    function varargout = subsref (x, idx)
+      varargout = num2cell (zeros (size (idx(1).subs{1})));
+    end
+  end
+end
diff -r beb7f91a0a97 -r a18897e4c7b5 test/bug-48693/module.mk
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/bug-48693/module.mk	Wed Dec 07 22:37:28 2022 -0500
@@ -0,0 +1,5 @@
+bug_48693_TEST_FILES = \
+  %reldir%/bug48693.m \
+  %reldir%/bug-48693.tst
+
+TEST_FILES += $(bug_48693_TEST_FILES)