percent sign in speech dispatcher

[Nicolas Graner]

Hello all,

when calling spd-say with a string that contains a percent sign, this
sign and the followind letter seem to be interpreted as a printf-like
format string.
Examples :

    spd-say "%d"
is spoken as "zero"
    spd-say "%f"
is spoken as "zero o o o o o o"
    spd-say "%s"
is spoken as "null"
    spd-say "%z"
prints an error message: Speech Dispatcher failed to say message

It does not seem to depend on the language or output module.

Is this a bug or a feature?

Thanks for your insights.
Nicolas