From 18e5ea50a7136cb3686c5a7c51c111ccce73dc54 Mon Sep 17 00:00:00 2001
From: Iris Morelle <shadowm@wesnoth.org>
Date: Sun, 6 May 2018 16:10:42 -0300
Subject: [PATCH] i18n: Blind fix attempt for std::bad_cast being thrown on
 Windows

Several reports on Steam and our forums point at std::bad_cast being
thrown when accessing Preferences and the Multiplayer menu amongst
others. It's possible that the locale configuration on those systems is
not quite right, and compare() and icompare() are able to throw
std::bad_cast when this happens as they both use std::use_facet().

Note that much like the macOS/iOS version of icompare(), this stopgap
patch doesn't attempt to provide any form of case-insensitive fallback
and just uses a case-sensitive comparison instead.
---
 src/gettext_boost.cpp | 29 +++++++++++++++++++++++++++--
 1 file changed, 27 insertions(+), 2 deletions(-)

diff --git a/src/gettext_boost.cpp b/src/gettext_boost.cpp
index 3cc7690d5ef..fb04ffeea90 100644
--- a/src/gettext_boost.cpp
+++ b/src/gettext_boost.cpp
@@ -423,7 +423,19 @@ void set_language(const std::string& language, const std::vector<std::string>* /
 int compare(const std::string& s1, const std::string& s2)
 {
 	std::lock_guard<std::mutex> lock(get_mutex());
-	return std::use_facet<std::collate<char>>(get_manager().get_locale()).compare(s1.c_str(), s1.c_str() + s1.size(), s2.c_str(), s2.c_str() + s2.size());
+
+	try {
+		return std::use_facet<std::collate<char>>(get_manager().get_locale()).compare(s1.c_str(), s1.c_str() + s1.size(), s2.c_str(), s2.c_str() + s2.size());
+	} catch(const std::bad_cast&) {
+		static bool bad_cast_once = false;
+
+		if(!bad_cast_once) {
+			ERR_G << "locale set-up for compare() is broken, falling back to std::string::compare()\n";
+			bad_cast_once = true;
+		}
+
+		return s1.compare(s2);
+	}
 }
 
 int icompare(const std::string& s1, const std::string& s2)
@@ -433,8 +445,21 @@ int icompare(const std::string& s1, const std::string& s2)
 	return compare(s1, s2);
 #else
 	std::lock_guard<std::mutex> lock(get_mutex());
-	return std::use_facet<bl::collator<char>>(get_manager().get_locale()).compare(
+
+	try {
+		return std::use_facet<bl::collator<char>>(get_manager().get_locale()).compare(
 			bl::collator_base::secondary, s1, s2);
+	} catch(const std::bad_cast&) {
+		static bool bad_cast_once = false;
+
+		if(!bad_cast_once) {
+			ERR_G << "locale set-up for icompare() is broken, falling back to std::string::compare()\n";
+			bad_cast_once = true;
+		}
+
+		// FIXME: not even lazily case-insensitive
+		return s1.compare(s2);
+	}
 #endif
 }