Fix: Don't rely on static initialization to set up sprite font caches.

The order of static initialization is undefined, so this can cause initalization
before relevant caches are initializations.

(cherry picked from commit f454ec8d63)

src/fontcache.cpp

@@ -54,7 +54,6 @@ int FontCache::GetDefaultFontHeight(FontSize fs)
 	return _default_font_height[fs];
 }
 
-/* static */ FontCache *FontCache::caches[FS_END] = { new SpriteFontCache(FS_NORMAL), new SpriteFontCache(FS_SMALL), new SpriteFontCache(FS_LARGE), new SpriteFontCache(FS_MONO) };
 int font_height_cache[FS_END];
 
 void UpdateFontHeightCache()
@@ -64,6 +63,15 @@ void UpdateFontHeightCache()
 	}
 }
 
+/* static */ FontCache *FontCache::caches[FS_END];
+
+/* static */ void FontCache::InitializeFontCaches()
+{
+	for (FontSize fs = FS_BEGIN; fs != FS_END; fs++) {
+		if (FontCache::caches[fs] == nullptr) new SpriteFontCache(fs); /* FontCache inserts itself into to the cache. */
+	}
+}
+
 /* Check if a glyph should be rendered with anti-aliasing. */
 bool GetFontAAState(FontSize size, bool check_blitter)
 {
@@ -131,6 +139,8 @@ extern void LoadCoreTextFont(FontSize fs);
  */
 void InitFontCache(bool monospace)
 {
+	FontCache::InitializeFontCaches();
+
 	for (FontSize fs = FS_BEGIN; fs < FS_END; fs++) {
 		if (monospace != (fs == FS_MONO)) continue;
 

src/fontcache.h

@@ -37,6 +37,8 @@ public:
 	FontCache(FontSize fs);
 	virtual ~FontCache();
 
+	static void InitializeFontCaches();
+
 	static int GetDefaultFontHeight(FontSize fs);
 
 	/**