bug#6532: text properties follow along text copied to other buffers

[jidanni]

Is it a bug or a feature that when I copy some glowing blue characters
to another buffer, they stay glowing blue, instead of adopting the drab
colors of other text that was typed into that buffer?

E.g., C-u C-x = shows this, even on text that was copied to a plain
text-mode buffer:

There are text properties here:
  balloon-help         nil
  face                 (w3m-anchor w3m-italic w3m-bold)
  rear-nonsticky       t
  w3m-anchor-sequence  23
  w3m-balloon-help     "http://www.youtube.com/watch?v=X9xWuvRaQ6g";
  w3m-href-anchor      "http://www.youtube.com/watch?v=X9xWuvRaQ6g";
  w3m-name-anchor      [Show]
  w3m-name-anchor2     ("tsf-oq" "logo" "gbe" "gbf" "gbn")
  w3m-safe-url-regexp  nil

Indeed, the only way I know to clean them up is
C-x h C-u <escape> | c a t <return>

emacs-version "24.0.50.1"