# HG changeset patch
# User John W. Eaton <jwe@octave.org>
# Date 1594300810 14400
# Node ID ac7ab2a9018e3c86e677131fda0a30d19c6b54ef
# Parent  3dae50cf0bc5fd0070f565eb8a75fd755806dd8d
create empty c-s list for x.a (bug #58695)

* ov-struct.cc (octave_struct::subsref): Create empty comma-separated
list if indexing operation creates empty cell array.
From Fernando Alvarruiz.

diff -r 3dae50cf0bc5 -r ac7ab2a9018e libinterp/octave-value/ov-struct.cc
--- a/libinterp/octave-value/ov-struct.cc	Thu Jul 09 09:15:58 2020 -0400
+++ b/libinterp/octave-value/ov-struct.cc	Thu Jul 09 09:20:10 2020 -0400
@@ -146,6 +146,9 @@
 
             const Cell t = tmp.index (idx.front ());
 
+            // Avoid creating a comma-separated list if the result is a
+            // single element.
+
             retval(0) = (t.numel () == 1) ? t(0) : octave_value (t, true);
 
             // We handled two index elements, so tell
@@ -162,8 +165,10 @@
       {
         const Cell t = dotref (idx.front ());
 
-        if (! map.isempty ())
-          retval(0) = (t.numel () == 1) ? t(0) : octave_value (t, true);
+        // Avoid creating a comma-separated list if the result is a
+        // single element.
+
+        retval(0) = (t.numel () == 1) ? t(0) : octave_value (t, true);
       }
       break;
 
@@ -207,6 +212,9 @@
 
             const Cell t = tmp.index (idx.front (), auto_add);
 
+            // Avoid creating a comma-separated list if the result is a
+            // single element.
+
             retval = (t.numel () == 1) ? t(0) : octave_value (t, true);
 
             // We handled two index elements, so tell
@@ -225,6 +233,9 @@
           {
             const Cell t = dotref (idx.front (), auto_add);
 
+            // Avoid creating a comma-separated list if the result is a
+            // single element.
+
             retval = (t.numel () == 1) ? t(0) : octave_value (t, true);
           }
       }