deprecate sparse_auto_mutate function and internal variable * sparse.cc (Fsparse): Don't set Vsparse_auto_mutate to false. * ov-base.h, ov-base.cc (Vsparse_auto_mutate): Deprecate variable. (Fsparse_auto_mutate): Delete function and tests. * ov-bool-sparse.h, ov-bool-sparse.cc (octave_sparse_bool_matrix::try_narrowing_conversion): Delete. * ov-re-sparse.h, ov-re-sparse.cc (octave_sparse_bool_matrix::try_narrowing_conversion): Delete. * ov-cx-sparse.cc (octave_sparse_complex_matrix::try_narrowing_conversion): Only perform complex sparse -> real sparse conversion. * scripts/deprecated/sparse_auto_mutate.m: New function. * scripts/deprecated/module.mk: Update. * sparse.txi: Remove documentation for sparse_auto_mutate.

--- a/libinterp/octave-value/ov-base.h	Wed Mar 02 20:31:46 2022 +0100
+++ b/libinterp/octave-value/ov-base.h	Wed Mar 02 15:01:30 2022 -0500
@@ -935,8 +935,7 @@
   octave::auto_shlib m_containing_dynamic_library;
 };
 
-// TRUE means to perform automatic sparse to real mutation if there
-// is memory to be saved
+OCTAVE_DEPRECATED (8, "Vsparse_auto_mutate is obsolete and is now always false")
 extern OCTINTERP_API bool Vsparse_auto_mutate;
 
 // Utility function to convert C++ arguments used in subsref/subsasgn into an