(svn r19914) -Codechange: Wrap a helper class around temporary assignments of _current_company to ensure proper restoration.

2 files changed, 23 insertions, 30 deletions

diff --git a/src/ai/ai_core.cpp b/src/ai/ai_core.cpp
index 02868e9bd..f61bc058c 100644
--- a/src/ai/ai_core.cpp
+++ b/src/ai/ai_core.cpp
@@ -10,6 +10,7 @@
 /** @file ai_core.cpp Implementation of AI. */
 
 #include "../stdafx.h"
+#include "../core/backup_type.hpp"
 #include "../core/bitmath_func.hpp"
 #include "../company_base.h"
 #include "../company_func.h"
@@ -68,13 +69,15 @@
 	assert(_settings_game.difficulty.competitor_speed <= 4);
 	if ((AI::frame_counter & ((1 << (4 - _settings_game.difficulty.competitor_speed)) - 1)) != 0) return;
 
+	Backup<CompanyByte> cur_company(_current_company);
 	const Company *c;
 	FOR_ALL_COMPANIES(c) {
 		if (c->is_ai) {
-			_current_company = c->index;
+			cur_company.Change(c->index);
 			c->ai_instance->GameLoop();
 		}
 	}
+	cur_company.Restore();
 
 	/* Occasionally collect garbage; every 255 ticks do one company.
 	 * Effectively collecting garbage once every two months per AI. */
@@ -82,8 +85,6 @@
 		CompanyID cid = (CompanyID)GB(AI::frame_counter, 8, 4);
 		if (Company::IsValidAiID(cid)) Company::Get(cid)->ai_instance->CollectGarbage();
 	}
-
-	_current_company = OWNER_NONE;
 }
 
 /* static */ uint AI::GetTick()
@@ -95,14 +96,13 @@
 {
 	if (_networking && !_network_server) return;
 
-	CompanyID old_company = _current_company;
-	_current_company = company;
+	Backup<CompanyByte> cur_company(_current_company, company);
 	Company *c = Company::Get(company);
 
 	delete c->ai_instance;
 	c->ai_instance = NULL;
 
-	_current_company = old_company;
+	cur_company.Restore();
 
 	InvalidateWindowData(WC_AI_DEBUG, 0, -1);
 	DeleteWindowById(WC_AI_SETTINGS, company);
@@ -112,11 +112,10 @@
 {
 	if (_networking && !_network_server) return;
 
-	CompanyID old_company = _current_company;
-	_current_company = company;
+	Backup<CompanyByte> cur_company(_current_company, company);
 	Company::Get(company)->ai_instance->Suspend();
 
-	_current_company = old_company;
+	cur_company.Restore();
 }
 
 /* static */ void AI::KillAll()
@@ -202,10 +201,9 @@
 	}
 
 	/* Queue the event */
-	CompanyID old_company = _current_company;
-	_current_company = company;
+	Backup<CompanyByte> cur_company(_current_company, company);
 	AIEventController::InsertEvent(event);
-	_current_company = old_company;
+	cur_company.Restore();
 
 	event->Release();
 }
@@ -249,10 +247,9 @@ void CcAI(const CommandCost &result, TileIndex tile, uint32 p1, uint32 p2)
 		Company *c = Company::GetIfValid(company);
 		assert(c != NULL && c->ai_instance != NULL);
 
-		CompanyID old_company = _current_company;
-		_current_company = company;
+		Backup<CompanyByte> cur_company(_current_company, company);
 		c->ai_instance->Save();
-		_current_company = old_company;
+		cur_company.Restore();
 	} else {
 		AIInstance::SaveEmpty();
 	}
@@ -264,10 +261,9 @@ void CcAI(const CommandCost &result, TileIndex tile, uint32 p1, uint32 p2)
 		Company *c = Company::GetIfValid(company);
 		assert(c != NULL && c->ai_instance != NULL);
 
-		CompanyID old_company = _current_company;
-		_current_company = company;
+		Backup<CompanyByte> cur_company(_current_company, company);
 		c->ai_instance->Load(version);
-		_current_company = old_company;
+		cur_company.Restore();
 	} else {
 		/* Read, but ignore, the load data */
 		AIInstance::LoadEmpty();
diff --git a/src/ai/ai_gui.cpp b/src/ai/ai_gui.cpp
index 57e8d0c24..afad432f6 100644
--- a/src/ai/ai_gui.cpp
+++ b/src/ai/ai_gui.cpp
@@ -26,6 +26,7 @@
 #include "../textbuf_gui.h"
 #include "../settings_func.h"
 #include "../network/network_content.h"
+#include "../core/backup_type.hpp"
 
 #include "ai.hpp"
 #include "api/ai_log.hpp"
@@ -819,10 +820,9 @@ struct AIDebugWindow : public QueryStringBaseWindow {
 			DrawCompanyIcon(i, button->pos_x + button->current_x / 2 - 7 + offset, this->GetWidget<NWidgetBase>(AID_WIDGET_COMPANY_BUTTON_START + i)->pos_y + 2 + offset);
 		}
 
-		CompanyID old_company = _current_company;
-		_current_company = ai_debug_company;
+		Backup<CompanyByte> cur_company(_current_company, ai_debug_company);
 		AILog::LogData *log = (AILog::LogData *)AIObject::GetLogPointer();
-		_current_company = old_company;
+		cur_company.Restore();
 
 		int scroll_count = (log == NULL) ? 0 : log->used;
 		if (this->vscroll.GetCount() != scroll_count) {
@@ -875,10 +875,9 @@ struct AIDebugWindow : public QueryStringBaseWindow {
 
 		switch (widget) {
 			case AID_WIDGET_LOG_PANEL: {
-				CompanyID old_company = _current_company;
-				_current_company = ai_debug_company;
+				Backup<CompanyByte> cur_company(_current_company, ai_debug_company);
 				AILog::LogData *log = (AILog::LogData *)AIObject::GetLogPointer();
-				_current_company = old_company;
+				cur_company.Restore();
 				if (log == NULL) return;
 
 				int y = this->top_offset;
@@ -915,10 +914,9 @@ struct AIDebugWindow : public QueryStringBaseWindow {
 		this->RaiseWidget(ai_debug_company + AID_WIDGET_COMPANY_BUTTON_START);
 		ai_debug_company = show_ai;
 
-		CompanyID old_company = _current_company;
-		_current_company = ai_debug_company;
+		Backup<CompanyByte> cur_company(_current_company, ai_debug_company);
 		AILog::LogData *log = (AILog::LogData *)AIObject::GetLogPointer();
-		_current_company = old_company;
+		cur_company.Restore();
 		this->vscroll.SetCount((log == NULL) ? 0 : log->used);
 
 		this->LowerWidget(ai_debug_company + AID_WIDGET_COMPANY_BUTTON_START);
@@ -1011,8 +1009,7 @@ struct AIDebugWindow : public QueryStringBaseWindow {
 		/* If the log message is related to the active company tab, check the break string */
 		if (data == ai_debug_company && this->break_check_enabled && !StrEmpty(this->edit_str_buf)) {
 			/* Get the log instance of the active company */
-			CompanyID old_company = _current_company;
-			_current_company = ai_debug_company;
+			Backup<CompanyByte> cur_company(_current_company, ai_debug_company);
 			AILog::LogData *log = (AILog::LogData *)AIObject::GetLogPointer();
 
 			if (log != NULL && case_sensitive_break_check?
@@ -1032,7 +1029,7 @@ struct AIDebugWindow : public QueryStringBaseWindow {
 				this->highlight_row = log->pos;
 			}
 
-			_current_company = old_company;
+			cur_company.Restore();
 		}
 	}