--- a/scripts/ChangeLog
+++ b/scripts/ChangeLog
@@ -1,3 +1,10 @@
+2008-03-26  John W. Eaton  <jwe@octave.org>
+
+	* set/ismember.m: Set size of idx output correctly for empty args.
+	New tests.
+
+	* general/logical.m: Correctly handle empty args.  New tests.
+
 2008-03-24  Thomas Weber  <thomas.weber.mail@gmail.com>
 
 	* pkg/pkg.m: Allow installation of already extracted packages.

--- a/scripts/general/logical.m
+++ b/scripts/general/logical.m
@@ -37,8 +37,10 @@
 function y = logical (x)
 
   if (nargin == 1)
-    if (islogical (x) || isempty (x))
+    if (islogical (x))
       y = x;
+    elseif (isempty (x))
+      y = zeros (size (x), "logical");
     elseif (isnumeric (x))
       y = x != 0;
     else
@@ -49,3 +51,12 @@
   endif
 
 endfunction
+
+%!assert (logical ([]), zeros ([0, 0], "logical"));
+%!assert (logical (zeros (2, 0)), zeros ([2, 0], "logical"));
+%!assert (logical (0), false);
+%!assert (logical (13), true);
+%!assert (logical (-13), true);
+%!assert (logical (int8 (13)), true);
+%!assert (logical (int8 (-13)), true);
+%!assert (logical ([-1, 0, 1, NaN, Inf]), [-1, 0, 1, NaN, Inf] != 0);

--- a/scripts/set/ismember.m
+++ b/scripts/set/ismember.m
@@ -119,7 +119,7 @@
         ## Do the actual work.
         if (isempty (a) || isempty (s))
           tf = zeros (size (a), "logical");
-          a_idx = []; 
+          a_idx = zeros (size (a)); 
         elseif (numel (s) == 1) 
           tf = (a == s);
           a_idx = double (tf);
@@ -165,12 +165,12 @@
           [v, p] = sort ([s(2:lt)(:); a(:)]); 
           idx(p) = cumsum (p <= lt-1) + 1; 
           idx = idx(lt:end); 
-          tf = (a == reshape (s (idx), size (a))); 
-          a_idx = zeros (size(tf)); 
+          tf = (a == reshape (s(idx), size (a))); 
+          a_idx = zeros (size (tf)); 
           a_idx(tf) = sidx(idx(tf));
         endif
         ## Resize result to the original size of 'a' 
-        size_a = size(a);
+        size_a = size (a);
         tf = reshape (tf, size_a); 
         a_idx = reshape (a_idx, size_a);
       endif
@@ -200,7 +200,7 @@
       ## Do the actual work
       if (isempty (a) || isempty (s))
         tf = zeros (size (a), "logical");
-        a_idx = []; 
+        a_idx = zeros (size (a)); 
       elseif (numel (s) == 1) 
         tf = strcmp (a, s);
         a_idx = double (tf);
@@ -257,6 +257,36 @@
 %!assert (ismember ("1", "0123456789."), true);
 
 %!test
+%! [result, a_idx] = ismember ([1, 2], []);
+%! assert (result, logical ([0, 0]))
+%! assert (a_idx, [0, 0]);
+
+%!test
+%! [result, a_idx] = ismember ([], [1, 2]);
+%! assert (result, logical ([]))
+%! assert (a_idx, []);
+
+%!test
+%! [result, a_idx] = ismember ({'a', 'b'}, '');
+%! assert (result, logical ([0, 0]))
+%! assert (a_idx, [0, 0]);
+
+%!test
+%! [result, a_idx] = ismember ({'a', 'b'}, {});
+%! assert (result, logical ([0, 0]))
+%! assert (a_idx, [0, 0]);
+
+%!test
+%! [result, a_idx] = ismember ('', {'a', 'b'});
+%! assert (result, false)
+%! assert (a_idx, 0);
+
+%!test
+%! [result, a_idx] = ismember ({}, {'a', 'b'});
+%! assert (result, logical ([]))
+%! assert (a_idx, []);
+
+%!test
 %! [result, a_idx] = ismember([1 2 3 4 5], [3]);
 %! assert (all (result == logical ([0 0 1 0 0])) && all (a_idx == [0 0 1 0 0]));