On load, use previous local company or first usable company

Instead of always using the first company slot

src/company_cmd.cpp

@@ -44,6 +44,7 @@ void ClearEnginesHiddenFlagOfCompany(CompanyID cid);
 
 CompanyID _local_company;   ///< Company controlled by the human player at this client. Can also be #COMPANY_SPECTATOR.
 CompanyID _current_company; ///< Company currently doing an action.
+CompanyID _loaded_local_company; ///< Local company in loaded savegame
 Colours _company_colours[MAX_COMPANIES];  ///< NOSAVE: can be determined from company structs.
 CompanyManagerFace _company_manager_face; ///< for company manager face storage in openttd.cfg
 uint _next_competitor_start;              ///< the number of ticks before the next AI is started
@@ -1184,6 +1185,20 @@ int CompanyServiceInterval(const Company *c, VehicleType type)
 	}
 }
 
+/**
+ * Get the default local company after loading a new game
+ */
+CompanyID GetDefaultLocalCompany()
+{
+	if (_loaded_local_company >= COMPANY_FIRST && _loaded_local_company < MAX_COMPANIES && Company::IsValidID(_loaded_local_company)) {
+		return _loaded_local_company;
+	}
+	for (CompanyID i = COMPANY_FIRST; i < MAX_COMPANIES; i++) {
+		if (Company::IsValidID(i)) return i;
+	}
+	return COMPANY_FIRST;
+}
+
 /**
  * Get total sum of all owned road bits.
  * @return Combined total road road bits.

src/company_func.h

@@ -32,6 +32,7 @@ CommandCost CheckTileOwnership(TileIndex tile);
 
 extern CompanyID _local_company;
 extern CompanyID _current_company;
+extern CompanyID _loaded_local_company;
 
 extern Colours _company_colours[MAX_COMPANIES];
 extern CompanyManagerFace _company_manager_face;
@@ -57,4 +58,6 @@ static inline bool IsInteractiveCompany(CompanyID company)
 
 int CompanyServiceInterval(const Company *c, VehicleType type);
 
+CompanyID GetDefaultLocalCompany();
+
 #endif /* COMPANY_FUNC_H */

src/misc.cpp

@@ -81,6 +81,7 @@ void InitializeGame(uint size_x, uint size_y, bool reset_date, bool reset_settin
 	_cur_tileloop_tile = 1;
 	_thd.redsq = INVALID_TILE;
 	_road_layout_change_counter = 0;
+	_loaded_local_company = COMPANY_SPECTATOR;
 	_game_events_since_load = (GameEventFlags) 0;
 	_game_events_overall = (GameEventFlags) 0;
 	_game_load_cur_date_ymd = { 0, 0, 0 };

src/network/network.cpp

@@ -717,7 +717,7 @@ static void NetworkInitGameInfo()
 	/* There should be always space for the server. */
 	assert(NetworkClientInfo::CanAllocateItem());
 	NetworkClientInfo *ci = new NetworkClientInfo(CLIENT_ID_SERVER);
-	ci->client_playas = _network_dedicated ? COMPANY_SPECTATOR : COMPANY_FIRST;
+	ci->client_playas = _network_dedicated ? COMPANY_SPECTATOR : GetDefaultLocalCompany();
 
 	strecpy(ci->client_name, _settings_client.network.client_name, lastof(ci->client_name));
 }

src/openttd.cpp

@@ -434,6 +434,7 @@ static void ShutdownGame()
 	ClearCommandLog();
 	ClearDesyncMsgLog();
 
+	_loaded_local_company = COMPANY_SPECTATOR;
 	_game_events_since_load = (GameEventFlags) 0;
 	_game_events_overall = (GameEventFlags) 0;
 	_game_load_cur_date_ymd = { 0, 0, 0 };
@@ -1233,8 +1234,8 @@ void SwitchToMode(SwitchMode new_mode)
 					EngineOverrideManager::ResetToCurrentNewGRFConfig();
 				}
 				/* Update the local company for a loaded game. It is either always
-				 * company #1 (eg 0) or in the case of a dedicated server a spectator */
-				SetLocalCompany(_network_dedicated ? COMPANY_SPECTATOR : COMPANY_FIRST);
+				 * a company or in the case of a dedicated server a spectator */
+				SetLocalCompany(_network_dedicated ? COMPANY_SPECTATOR : GetDefaultLocalCompany());
 				if (_ctrl_pressed && !_network_dedicated) {
 					DoCommandP(0, PM_PAUSED_NORMAL, 1, CMD_PAUSE);
 				}

src/saveload/afterload.cpp

@@ -970,9 +970,8 @@ bool AfterLoadGame()
 	 *  a company does not exist yet. So create one here.
 	 * 1 exception: network-games. Those can have 0 companies
 	 *   But this exception is not true for non-dedicated network servers! */
-	if (!Company::IsValidID(COMPANY_FIRST) && (!_networking || (_networking && _network_server && !_network_dedicated))) {
-		DoStartupNewCompany(false);
-		Company *c = Company::Get(COMPANY_FIRST);
+	if (!Company::IsValidID(GetDefaultLocalCompany()) && (!_networking || (_networking && _network_server && !_network_dedicated))) {
+		Company *c = DoStartupNewCompany(false);
 		c->settings = _settings_client.company;
 	}
 

src/saveload/extended_ver_sl.cpp

@@ -44,6 +44,7 @@
 #include "../map_func.h"
 #include "../rev.h"
 #include "../strings_func.h"
+#include "../company_func.h"
 #include "table/strings.h"
 
 #include <vector>
@@ -62,6 +63,8 @@ static const uint32 _sl_xv_slxi_chunk_version = 0;          ///< current version
 
 static void loadVL(const SlxiSubChunkInfo *info, uint32 length);
 static uint32 saveVL(const SlxiSubChunkInfo *info, bool dry_run);
+static void loadLC(const SlxiSubChunkInfo *info, uint32 length);
+static uint32 saveLC(const SlxiSubChunkInfo *info, bool dry_run);
 
 const SlxiSubChunkInfo _sl_xv_sub_chunk_infos[] = {
 	{ XSLFI_VERSION_LABEL,          XSCF_IGNORABLE_ALL,       1,   1, "version_label",             saveVL,  loadVL,  nullptr        },
@@ -129,6 +132,7 @@ const SlxiSubChunkInfo _sl_xv_sub_chunk_infos[] = {
 	{ XSLFI_TOWN_MULTI_BUILDING,    XSCF_NULL,                1,   1, "town_multi_building",       nullptr, nullptr, nullptr        },
 	{ XSLFI_SHIP_LOST_COUNTER,      XSCF_NULL,                1,   1, "ship_lost_counter",         nullptr, nullptr, nullptr        },
 	{ XSLFI_BUILD_OBJECT_RATE_LIMIT,XSCF_NULL,                1,   1, "build_object_rate_limit",   nullptr, nullptr, nullptr        },
+	{ XSLFI_LOCAL_COMPANY,          XSCF_IGNORABLE_ALL,       1,   1, "local_company",             saveLC,  loadLC,  nullptr        },
 	{ XSLFI_NULL, XSCF_NULL, 0, 0, nullptr, nullptr, nullptr, nullptr },// This is the end marker
 };
 
@@ -627,6 +631,22 @@ static uint32 saveVL(const SlxiSubChunkInfo *info, bool dry_run)
 	return length;
 }
 
+static void loadLC(const SlxiSubChunkInfo *info, uint32 length)
+{
+	if (length == 1) {
+		_loaded_local_company = (CompanyID) ReadBuffer::GetCurrent()->ReadByte();
+	} else {
+		DEBUG(sl, 1, "SLXI chunk: feature: '%s', version: %d, has data of wrong length: %u", info->name, _sl_xv_feature_versions[info->index], length);
+		ReadBuffer::GetCurrent()->SkipBytes(length);
+	}
+}
+
+static uint32 saveLC(const SlxiSubChunkInfo *info, bool dry_run)
+{
+	if (!dry_run) MemoryDumper::GetCurrent()->WriteByte(_local_company);
+	return 1;
+}
+
 extern const ChunkHandler _version_ext_chunk_handlers[] = {
 	{ 'SLXI', Save_SLXI, Load_SLXI, nullptr, Load_SLXI, CH_RIFF | CH_LAST},
 };

src/saveload/extended_ver_sl.h

@@ -86,6 +86,7 @@ enum SlXvFeatureIndex {
 	XSLFI_TOWN_MULTI_BUILDING,                    ///< Allow multiple stadium/church buildings in a single town
 	XSLFI_SHIP_LOST_COUNTER,                      ///< Ship lost counter
 	XSLFI_BUILD_OBJECT_RATE_LIMIT,                ///< Build object rate limit
+	XSLFI_LOCAL_COMPANY,                          ///< Local company ID
 
 	XSLFI_RIFF_HEADER_60_BIT,                     ///< Size field in RIFF chunk header is 60 bit
 	XSLFI_HEIGHT_8_BIT,                           ///< Map tile height is 8 bit instead of 4 bit, but savegame version may be before this became true in trunk