Remove allocation on translation key lookup

Common/Data/Text/I18n.cpp

@@ -78,26 +78,24 @@ const char *I18NCategory::T(const char *key, const char *def) {
 	}
 
 	// Replace the \n's with \\n's so that key values with newlines will be found correctly.
-	std::string modifiedKey = key;
-	modifiedKey = ReplaceAll(modifiedKey, "\n", "\\n");
-
-	auto iter = map_.find(modifiedKey);
+	auto iter = map_.find(key);
 	if (iter != map_.end()) {
 		return iter->second.text.c_str();
 	} else {
 		std::lock_guard<std::mutex> guard(missedKeyLock_);
 		if (def)
 			missedKeyLog_[key] = def;
 		else
-			missedKeyLog_[key] = modifiedKey;
+			missedKeyLog_[key] = key;
 		return def ? def : key;
 	}
 }
 
 void I18NCategory::SetMap(const std::map<std::string, std::string> &m) {
 	for (auto iter = m.begin(); iter != m.end(); ++iter) {
 		if (map_.find(iter->first) == map_.end()) {
-			std::string text = ReplaceAll(iter->second, "\\n", "\n");
+			std::string text = ReplaceAll(iter->second, "\n", "\\n");
+			_dbg_assert_(iter->first.find('\n') == std::string::npos);
 			map_[iter->first] = I18NEntry(text);
 		}
 	}

Common/Data/Text/I18n.h

@@ -91,15 +91,15 @@ class I18NCategory {
 		return missedKeyLog_;
 	}
 
-	const std::map<std::string, I18NEntry> &GetMap() { return map_; }
+	const std::map<std::string, I18NEntry, std::less<>> &GetMap() { return map_; }
 	void ClearMissed() { missedKeyLog_.clear(); }
 	void Clear();
 
 private:
 	I18NCategory(I18NRepo *repo, const char *name) {}
 	void SetMap(const std::map<std::string, std::string> &m);
 
-	std::map<std::string, I18NEntry> map_;
+	std::map<std::string, I18NEntry, std::less<>> map_;
 	mutable std::mutex missedKeyLock_;
 	std::map<std::string, std::string> missedKeyLog_;