draw_segment() call to tile_to_canvas_pos() clang analyzer NULL dereference warning
I think that the warning is sort of regression introduced by #47894. Not as serious as regressions usually are, as one could also interpret this so that the warning that existed prior to #47894 is now just produced about more apt place (not about all tile_to_canvas_pos() calls but specifically about the draw_segment() one)
Clang analyzer warns that draw_segment() may pass NULL as third parameter to tile_to_canvas_pos().