# HG changeset patch
# User Rik <rik@octave.org>
# Date 1682042337 25200
# Node ID f18da620ab4dabd0dcc6ce7a687a2659a5e15829
# Parent  1824e0ee40885d1a23754c5d047ae2bbb8436d33
Fix floating point exception when Sparse array reshaped to 0x0 (bug #64080)

* Sparse.cc (reshape): Test for empty matrix (number of rows or columns equal
to 0) and immediately return constructed, but unfilled, empty sparse matrix.

* data.cc (Freshape): Add BIST test for bug #64080.

diff -r 1824e0ee4088 -r f18da620ab4d libinterp/corefcn/data.cc
--- a/libinterp/corefcn/data.cc	Tue Apr 18 11:09:17 2023 -0700
+++ b/libinterp/corefcn/data.cc	Thu Apr 20 18:58:57 2023 -0700
@@ -5981,6 +5981,8 @@
 %!assert (size (reshape (ones (15, 4, "single"), 1, 60)), [1, 60])
 %!assert (size (reshape (ones (15, 4, "single"), 60, 1)), [60, 1])
 
+%!assert <*64080> (size (reshape (sparse (0, 1), 0, 0)), [0, 0])
+
 %!test
 %! s.a = 1;
 %! fail ("reshape (s, 2, 3)", "can't reshape 1x1 array to 2x3 array");
diff -r 1824e0ee4088 -r f18da620ab4d liboctave/array/Sparse.cc
--- a/liboctave/array/Sparse.cc	Tue Apr 18 11:09:17 2023 -0700
+++ b/liboctave/array/Sparse.cc	Thu Apr 20 18:58:57 2023 -0700
@@ -873,6 +873,9 @@
           octave_idx_type old_nr = rows ();
           octave_idx_type old_nc = cols ();
           retval = Sparse<T, Alloc> (new_nr, new_nc, new_nnz);
+          // Special case for empty matrices (bug #64080)
+          if (new_nr == 0 || new_nc == 0)
+            return retval;
 
           octave_idx_type kk = 0;
           retval.xcidx (0) = 0;