# HG changeset patch
# User Rik <rik@octave.org>
# Date 1664928321 25200
# Node ID fa4bb329a51a32869624d7b69c13b7459d713c37
# Parent  43068d904d9df49d122c4e1741feb2d97e509061
Allow empty sparse matrix inputs to qr() (bug #63069)

* qr.cc (Fqr): Add BIST tests for bug #63069.

* sparse-qr.cc (sparse_qr<SparseMatrix>::sparse_qr_rep::sparse_qr_rep,
sparse_qr<SparseMatrix>::sparse_qr_rep::C,
sparse_qr<SparseMatrix>::sparse_qr_rep::tall_solve<MArray<double>, Matrix>,
sparse_qr<SparseComplexMatrix>::sparse_qr_rep::sparse_qr_rep,
sparse_qr<SparseComplexMatrix>::sparse_qr_rep::C,
sparse_qr<SPARSE_T>::solve):
Change input validation from "<= 0" to "< 0".
Change error message to "matrix dimension with negative size" from
"matrix dimension with negative or zero size".

diff -r 43068d904d9d -r fa4bb329a51a libinterp/corefcn/qr.cc
--- a/libinterp/corefcn/qr.cc	Tue Oct 04 16:58:14 2022 -0400
+++ b/libinterp/corefcn/qr.cc	Tue Oct 04 17:05:21 2022 -0700
@@ -800,11 +800,17 @@
 %! assert (r, re, sqrt (eps));
 %! assert (q'*b, c, sqrt (eps));
 
+## Empty matrices
 %!test
 %! assert (qr (zeros (0, 0)), zeros (0, 0))
 %! assert (qr (zeros (1, 0)), zeros (1, 0))
 %! assert (qr (zeros (0, 1)), zeros (0, 1))
 
+%!test <*63069>
+%! assert (qr (sparse (0, 0)), sparse (0, 0))
+%! assert (qr (sparse (1, 0)), sparse (1, 0))
+%! assert (qr (sparse (0, 1)), sparse (0, 1))
+
 %!error qr ()
 %!error qr ([1, 2; 3, 4], 0, 2)
 %!error <option string must be .*, not "foo"> qr (magic (3), "foo")
diff -r 43068d904d9d -r fa4bb329a51a liboctave/numeric/sparse-qr.cc
--- a/liboctave/numeric/sparse-qr.cc	Tue Oct 04 16:58:14 2022 -0400
+++ b/liboctave/numeric/sparse-qr.cc	Tue Oct 04 17:05:21 2022 -0700
@@ -509,9 +509,9 @@
       octave_idx_type nr = a.rows ();
       octave_idx_type nc = a.cols ();
 
-      if (nr <= 0 || nc <= 0)
+      if (nr < 0 || nc < 0)
         (*current_liboctave_error_handler)
-          ("matrix dimension with negative or zero size");
+          ("matrix dimension with negative size");
 
       if (order < 0 || order > 9)
         (*current_liboctave_error_handler)
@@ -707,9 +707,9 @@
       if (nrows != b_nr)
         (*current_liboctave_error_handler)
           ("sparse_qr: matrix dimension mismatch");
-      else if (b_nc <= 0 || b_nr <= 0)
+      else if (b_nc < 0 || b_nr < 0)
         (*current_liboctave_error_handler)
-          ("sparse_qr: matrix dimension with negative or zero size");
+          ("sparse_qr: matrix dimension with negative size");
 
       cholmod_dense *QTB;  // Q' * B
       cholmod_dense B = rod2rcd (b);
@@ -904,9 +904,9 @@
       octave_idx_type b_nc = b.cols ();
       Matrix x (ncols, b_nc);  // X = m_E'*(m_R\(Q'*B))
 
-      if (nrows <= 0 || ncols <= 0 || b_nc <= 0 || b_nr <= 0)
+      if (nrows < 0 || ncols < 0 || b_nc < 0 || b_nr < 0)
         (*current_liboctave_error_handler)
-          ("matrix dimension with negative or zero size");
+          ("matrix dimension with negative size");
 
       if (nrows < 0 || ncols < 0 || nrows != b_nr)
         (*current_liboctave_error_handler) ("matrix dimension mismatch");
@@ -1444,9 +1444,9 @@
       octave_idx_type nr = a.rows ();
       octave_idx_type nc = a.cols ();
 
-      if (nr <= 0 || nc <= 0)
+      if (nr < 0 || nc < 0)
         (*current_liboctave_error_handler)
-          ("matrix dimension with negative or zero size");
+          ("matrix dimension with negative size");
 
       if (order < 0 || order > 9)
         (*current_liboctave_error_handler)
@@ -1643,9 +1643,9 @@
       if (nrows != b_nr)
         (*current_liboctave_error_handler) ("matrix dimension mismatch");
 
-      if (b_nc <= 0 || b_nr <= 0)
+      if (b_nc < 0 || b_nr < 0)
         (*current_liboctave_error_handler)
-          ("matrix dimension with negative or zero size");
+          ("matrix dimension with negative size");
 
       cholmod_dense *QTB;  // Q' * B
       cholmod_dense B = cod2ccd (b);
@@ -3118,9 +3118,9 @@
 
       int order = cxsparse_defaults<SPARSE_T>::order;
 
-      if (nr <= 0 || nc <= 0 || b_nc <= 0 || b_nr <= 0)
+      if (nr < 0 || nc < 0 || b_nc < 0 || b_nr < 0)
         (*current_liboctave_error_handler)
-          ("matrix dimension with negative or zero size");
+          ("matrix dimension with negative size");
 
       if ( nr != b_nr)
         (*current_liboctave_error_handler)