Merge branch 'master' into jgrpp

# Conflicts:
#	.github/workflows/release-macos.yml
#	src/company_gui.cpp
#	src/linkgraph/linkgraph.cpp
#	src/newgrf_debug_gui.cpp
#	src/strgen/strgen_base.cpp
#	src/timetable_gui.cpp

src/gfx_type.h

@@ -281,6 +281,9 @@ enum TextColour {
 	TC_IS_PALETTE_COLOUR = 0x100, ///< Colour value is already a real palette colour index, not an index of a StringColour.
 	TC_NO_SHADE          = 0x200, ///< Do not add shading to this text colour.
 	TC_FORCED            = 0x400, ///< Ignore colour changes from strings.
+
+	TC_COLOUR_MASK = 0xFF, ///< Mask to test if TextColour (without flags) is within limits.
+	TC_FLAGS_MASK = 0x700, ///< Mask to test if TextColour (with flags) is within limits.
 };
 DECLARE_ENUM_AS_BIT_SET(TextColour)