D01 test failure for prompts in dumb terminal

[Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx>]

Subsequent to workers/51297 --

In an xterm or gnome terminal, test D01 succeeds.

In a shell running in an emacs buffer, I get (trimmed from ZTST_verbose=1)

Running test: Equivalence of terminal colour settings (foreground colour)
Test case skipped: Missing terminfo module or non-colour terminal
Running test: Equivalence of terminal colour settings (background colour)
Test case skipped: Missing terminfo module or non-colour terminal
Running test: Attribute optimisation - preserve initial disabling of
attribute but drop useless later one
Test ./D01prompt.ztst failed: bad status 1, expected 0 from:
  A1=${(%):-%s}
  A2=${(%):-%u}
  A3=${(%):-%s%u%s}
  [[ $A3 = $A1$A2 && -n $A1 && -n $A2 ]]
Was testing: Attribute optimisation - preserve initial disabling of
attribute but drop useless later one

With ZTST_continue=1, that is the only test that fails.  Perhaps it
also needs to be skipped?