Bugfix #24986

When duplicating a mesh that has a mask modifier on it,
the invert option of that modifier dis not copy over.

Report + fix provided by Jacob F. Thanks!

source/blender/modifiers/intern/MOD_mask.c

@@ -53,6 +53,7 @@ static void copyData(ModifierData *md, ModifierData *target)
 	MaskModifierData *tmmd = (MaskModifierData*) target;
 	
 	strcpy(tmmd->vgroup, mmd->vgroup);
+	tmmd->flag = mmd->flag;
 }
 
 static CustomDataMask requiredDataMask(Object *UNUSED(ob), ModifierData *UNUSED(md))