Match Matlab return dimensions for find on empty sparse matrices (bug #42408). * find.cc (find_nonzero_elem_idx (const Sparse<T>& v)): Match Matlab return dimensions for odd cases such as 0x1, 1x0, 1x1(empty) sparse matrices. The conditions are documented in Array.cc (Array<T>::find) and are already implemented for other array types besides sparse. * find.cc (find_nonzero_elem_idx (const PermMatrix& v)): Match Matlab return dimensions for odd cases such as 0x1, 1x0, 1x1(empty) permutation matrices.

EXTRA_DIST += \
  m4/module.mk \
  m4/ax_blas.m4 \
  m4/ax_blas_f77_func.m4 \
  m4/ax_compare_version.m4 \
  m4/ax_lapack.m4 \
  m4/ax_pthread.m4 \
  m4/gnulib-cache.m4 \
  m4/libtool.m4 \
  m4/ltoptions.m4 \
  m4/ltsugar.m4 \
  m4/ltversion.m4 \
  m4/lt~obsolete.m4 \
  m4/pkg.m4