Nebula: pAI savefiles cause strange runtimes

[out-of-phaze]

Description of Issue

pAI savefiles cause strange runtimes, seemingly from the savefile being null?

Code sample

Lines 15-29 of personality.dm:

/datum/paiCandidate/proc/savefile_save(mob/user)
	if(IsGuestKey(user.key))
		return 0

	var/savefile/F = new /savefile(src.savefile_path(user))

	to_file(F["name"], src.name)
	to_file(F["description"], src.description)
	to_file(F["role"], src.role)
	to_file(F["comments"], src.comments)
	to_file(F["chassis"], src.chassis)
	to_file(F["say_verb"], src.say_verb)
	to_file(F["version"], 1)

	return 1

Logs

[23:59:59] Runtime in ,0: Deserialization of types without a parameterless constructor, a singular parameterized constructor, or a parameterized constructor annotated with 'JsonConstructorAttribute' is not supported. Type 'OpenDreamRuntime.Objects.Types.DreamObjectSavefile+SFDreamJsonValue'. Path: $ | LineNumber: 0 | BytePositionInLine: 5.
  Exception occurred: Deserialization of types without a parameterless constructor, a singular parameterized constructor, or a parameterized constructor annotated with 'JsonConstructorAttribute' is not supported. Type 'OpenDreamRuntime.Objects.Types.DreamObjectSavefile+SFDreamJsonValue'. Path: $ | LineNumber: 0 | BytePositionInLine: 5.

  =DM StackTrace=

   new /savefile

   /datum/paiCandidate/savefile_save code/modules/mob/living/silicon/pai/personality.dm:19

   /datum/category_item/player_setup_item/player_global/pai/save_preferences code/modules/client/preference_setup/global/03_pai.dm:27

   /datum/category_group/player_setup_category/save_preferences code/modules/client/preference_setup/preference_setup.dm:157

   /datum/category_collection/player_setup_collection/save_preferences code/modules/client/preference_setup/preference_setup.dm:90

   /datum/preferences/save_preferences code/modules/client/preferences_persist.dm:66

   /datum/preferences/Topic code/modules/client/preferences.dm:308

   /client/Topic Types/Client.dm:69

   /client/Topic code/modules/client/client_procs.dm:108

  =C# StackTrace=

  System.NotSupportedException: Deserialization of types without a parameterless constructor, a singular parameterized constructor, or a parameterized constructor annotated with 'JsonConstructorAttribute' is not supported. Type 'OpenDreamRuntime.Objects.Types.DreamObjectSavefile+SFDreamJsonValue'. Path: $ | LineNumber: 0 | BytePositionInLine: 5.

   ---> System.NotSupportedException: Deserialization of types without a parameterless constructor, a singular parameterized constructor, or a parameterized constructor annotated with 'JsonConstructorAttribute' is not supported. Type 'OpenDreamRuntime.Objects.Types.DreamObjectSavefile+SFDreamJsonValue'.

   --- End of inner exception stack trace ---

   at System.Text.Json.ThrowHelper.ThrowNotSupportedException(ReadStack& state, Utf8JsonReader& reader, NotSupportedException ex)

   at System.Text.Json.Serialization.Converters.ObjectDefaultConverter`1.OnTryRead(Utf8JsonReader& reader, Type typeToConvert, JsonSerializerOptions options, ReadStack& state, T& value)

   at System.Text.Json.Serialization.JsonConverter`1.TryRead(Utf8JsonReader& reader, Type typeToConvert, JsonSerializerOptions options, ReadStack& state, T& value, Boolean& isPopulatedValue)

   at System.Text.Json.Serialization.JsonConverter`1.ReadCore(Utf8JsonReader& reader, JsonSerializerOptions options, ReadStack& state)

   at System.Text.Json.JsonSerializer.ReadFromSpan[TValue](ReadOnlySpan`1 utf8Json, JsonTypeInfo`1 jsonTypeInfo, Nullable`1 actualByteCount)

   at System.Text.Json.JsonSerializer.ReadFromSpan[TValue](ReadOnlySpan`1 json, JsonTypeInfo`1 jsonTypeInfo)

   at System.Text.Json.JsonSerializer.Deserialize[TValue](String json, JsonSerializerOptions options)

   at OpenDreamRuntime.Objects.Types.DreamObjectSavefile.Initialize(DreamProcArguments args) in c:\Users\User\phaze\OpenDream\OpenDreamRuntime\Objects\Types\DreamObjectSavefile.cs:line 106

   at OpenDreamRuntime.Procs.InitDreamObjectState.Resume() in c:\Users\User\phaze\OpenDream\OpenDreamRuntime\Procs\InitDreamObject.cs:line 80

   at OpenDreamRuntime.DreamThread.Resume() in c:\Users\User\phaze\OpenDream\OpenDreamRuntime\DreamThread.cs:line 223

[ERRO] world.log: Exception occurred: Cannot get index "name" of null
=DM StackTrace=
   /datum/paiCandidate/savefile_save code/modules/mob/living/silicon/pai/personality.dm:21
   /datum/category_item/player_setup_item/player_global/pai/save_preferences code/modules/client/preference_setup/global/03_pai.dm:27
   /datum/category_group/player_setup_category/save_preferences code/modules/client/preference_setup/preference_setup.dm:157
   /datum/category_collection/player_setup_collection/save_preferences code/modules/client/preference_setup/preference_setup.dm:90
   /datum/preferences/save_preferences code/modules/client/preferences_persist.dm:66
   /datum/preferences/Topic code/modules/client/preferences.dm:308
   /client/Topic Types/Client.dm:69
   /client/Topic code/modules/client/client_procs.dm:108

=C# StackTrace=
System.Exception: Cannot get index "name" of null
   at OpenDreamRuntime.Procs.DMProcState.ThrowCannotGetIndex(DreamValue indexing, DreamValue index) in c:\Users\User\phaze\OpenDream\OpenDreamRuntime\Procs\DMProc.cs:line 922
   at OpenDreamRuntime.Procs.DMProcState.GetIndex(DreamValue indexing, DreamValue index) in c:\Users\User\phaze\OpenDream\OpenDreamRuntime\Procs\DMProc.cs:line 916
   at OpenDreamRuntime.Procs.DMProcState.GetReferenceValue(DreamReference reference, Boolean peek) in c:\Users\User\phaze\OpenDream\OpenDreamRuntime\Procs\DMProc.cs:line 809
   at OpenDreamRuntime.Procs.DMOpcodeHandlers.OutputReference(DMProcState state) in c:\Users\User\phaze\OpenDream\OpenDreamRuntime\Procs\DMOpcodeHandlers.cs:line 2185
   at OpenDreamRuntime.Procs.DMProcState.Resume() in c:\Users\User\phaze\OpenDream\OpenDreamRuntime\Procs\DMProc.cs:line 415
   at OpenDreamRuntime.DreamThread.Resume() in c:\Users\User\phaze\OpenDream\OpenDreamRuntime\DreamThread.cs:line 223

[amylizzle]

I think this is from trying to load a savefile in a bad (ie, BYOND) format. The loading runtimes and the savefile returned is null. Could definitely use a cleaner error message there though.