player: add option-info/<name>/expects-file

This will allow console.lua to complete files after e.g. set
glsl-shaders <Tab>.

DOCS/interface-changes/option-info-expects-file.txt

@@ -0,0 +1 @@
+add "option-info/<name>/expects-file" sub-property

DOCS/man/input.rst

@@ -3678,6 +3678,9 @@ Property list
         means the option value will be restored to the value before playback
         start when playback ends.
 
+    ``option-info/<name>/expects-file``
+        Whether the option takes file paths as arguments.
+
     ``option-info/<name>/default-value``
         The default value of the option. May not always be available.
 

player/command.c

@@ -3650,6 +3650,7 @@ static int mp_property_option_info(void *ctx, struct m_property *prop,
             {"type",                    SUB_PROP_STR(opt->type->name)},
             {"set-from-commandline",    SUB_PROP_BOOL(co->is_set_from_cmdline)},
             {"set-locally",             SUB_PROP_BOOL(co->is_set_locally)},
+            {"expects-file",            SUB_PROP_BOOL(opt->flags & M_OPT_FILE)},
             {"default-value",           *opt, def},
             {"min",                     SUB_PROP_DOUBLE(opt->min),
              .unavailable = !(has_minmax && opt->min != DBL_MIN)},

player/lua/console.lua

@@ -934,7 +934,7 @@ local function property_list()
 
         for _, sub_property in pairs({
             'name', 'type', 'set-from-commandline', 'set-locally',
-            'default-value', 'min', 'max', 'choices',
+            'expects-file', 'default-value', 'min', 'max', 'choices',
         }) do
             properties[#properties + 1] = 'option-info/' .. option .. '/' ..
                                           sub_property