Merge branch 'jgrpp' into jgrpp-beta

# Conflicts:
#	src/settings.cpp
#	src/settings_gui.cpp
#	src/settings_internal.h
#	src/table/company_settings.ini
#	src/table/currency_settings.ini
#	src/table/gameopt_settings.ini
#	src/table/misc_settings.ini
#	src/table/settings.h.preamble
#	src/table/settings.ini
#	src/table/win32_settings.ini
#	src/table/window_settings.ini

src/newgrf.cpp

@@ -5393,6 +5393,11 @@ static void NewSpriteGroup(ByteReader *buf)
 						return;
 					}
 
+					if (num_loaded + num_loading == 0) {
+						grfmsg(1, "NewSpriteGroup: no result, skipping invalid RealSpriteGroup");
+						break;
+					}
+
 					assert(RealSpriteGroup::CanAllocateItem());
 					RealSpriteGroup *group = new RealSpriteGroup();
 					group->nfo_line = _cur.nfo_line;