misbehavior in shell window with ksh

[Mike Kupfer]

>From emacs -Q, using Emacs master 6fa9cc05, if I do the following steps

  M-x shell RET
  ksh RET
  C-x o RET
  C-x 0 RET
  
a ">" appears after the shell prompt in the *shell* buffer:

  alto$ ksh
  alto$ >

If I then press RET, I get

  alto$ ksh
  alto$ > 
  : not found [No such file or directory]
  alto$

I've reproduced this behavior a couple different recent versions of
Emacs, including 25.1.91 and 25.2-rc2.  And I've reproduced it on both
Solaris 11 and Debian 8.

Using the version of Emacs that is packaged with Debian 8 (24.4), I
don't see any problems.

TERM is set to dumb; changing it to emacs doesn't help.

Can anyone else reproduce this behavior?

thanks,
mike