I use gvim as an external text editor and it always bugs me that after closing gvim and coming back to the compose window there is no syntax highlighting whatsoever. Editing the text on a certain line within the compose window brings back highlighting from that line onward only. I discovered by accident that using paste (CTRL-V) in the compose window restores highlighting for the whole text. So it should be easy to use whatever highlighting code is executed after pasting also after rereading the externally edited text.
(In reply to Jazz Fan from comment #0) > So it should be easy... We're waiting for your patch.
(In reply to Paul from comment #1) Thanks for the vote of confidence, but although I have a little programming experience I doubt that I would rise to the task with my abilities, especially since I have never mastered GDK/GTK programming.