Add function "dir_encoding" to set a file encoding per directory (bug #49685). * corefcn/load-path.h (load_path::read_dir_config): Add new function. * corefcn/load-path.cc (load_path::read_dir_config): Add new function. (load_path::add): Call read_dir_config on adding a new directory to the load path. * corefcn/input.h (input_system::dir_encoding, input_system::set_dir_encoding): Add new functions. Add private unordered_map "m_dir_encoding". * corefcn/input.cc (input_system::dir_encoding, input_system::set_dir_encoding): Add new functions. (base_reader, file_reader, input_reader): Add new constructors that accept an encoding (use mfile_encoding by default). Add private property "m_encoding". (load_path_dir): Static function to get the part of the directory that would be added to the load path. (Fdir_encoding): New function. * corefcn/interpreter.cc (interpreter::chdir): Call load_path::read_dir_config. * parse-tree/lex.h (lexer): Add new constructor that accepts an encoding. * parse-tree/parse.h (parser): Add new constructor that accepts an encoding. * parse-tree/oct-parse.yy (parse_fcn_file): Pass dir_encoding to parser. * doc/interpreter/func.txi: Add docstring of function "dir_encoding" to manual.

--- a/libinterp/parse-tree/parse.h	Sat Oct 17 02:13:39 2020 -0700
+++ b/libinterp/parse-tree/parse.h	Fri Sep 18 17:15:32 2020 +0200
@@ -610,6 +610,10 @@
       : base_parser (*(new lexer (file, interp)))
     { }
 
+    parser (FILE *file, interpreter& interp, std::string encoding)
+      : base_parser (*(new lexer (file, interp, encoding)))
+    { }
+
     parser (const std::string& eval_string, interpreter& interp)
       : base_parser (*(new lexer (eval_string, interp)))
     { }