[Clock] Microsecond format-code does not affect update interval

Hi,

I'm using the following custom format on the xfce4-panel clock plugin: %H:%M:%S.%f. The interesting format-code for this bug-report is the %f part, which outputs the number of microseconds within the current second.

The behavior I had expected upon adding the %f format-code was sub second updates to the clock, similar to how adding the %S format-code results in sub minute updates to the clock.

What is observed however is that adding the %f format-code has no impact on the update interval of the clock.

The issue can be easily reproduced using the format string: %M %f, upon which updates are only generated every minute, or by using the format string: %S %f, upon which updates are only generated every second.

If I jiggle my mouse over the clock I get sub second updates, I assume from UI events.

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This seems to be the code relevant for deciding the update interval: Which checks for a variety of format-codes, including %S and if found configures the update interval to be by the second, rather than by the minute. The %f modifier gets no special treatment in the function whatsoever.

This seems to be the code relevant for configuring when the next update should occur: It seems clear here that the update interval is thought of a binary between updates by the second and by the minute.