Calc Defect

How do I report a found flaw in the software. Here?

Try this:
Start a new LibreOffice Calc
select any cell and format it to time 876613:37:46 format code [HH]:MM:SS
now enter a time like 10:05:22 (this is 10hr 5min 22sec)
Above looks good, right!
Now enter 10:11:22 (10hr 11min 22sec)
What do you see? Problem?
If you have the same problem you will notice this happens from any time between
10:10:00 to 10:13:59

Funny, you can enter a time like 10:09:62 and 10:10:02 will display. But you can
not enter 10:10:02 directly.

I have come across other times that do the same, but didn't keep a record of
which ones. This happens across OS platforms and versions.

I first found this problem when I installed LibreOffice ver 5.1.0.3 x64 on Windows.
I found the same problem on my Linux Mint 17.3 LibreOffice 5.0.3.2

I would like to start using LibreOffice but I have switched back to Open Office
because I need this time format to work.

Thank You
Russell England

@Russell,

That is the autocorrect support for emoji replacing the string with a single
Unicode emoji from the SMP--clock faces for 10, 11, and 12. The string is
replaced with the single emoji, but then does not show in the font in use.

Already reported tdf#97191
<https://bugs.documentfoundation.org/show_bug.cgi?id=97191> .

Simple to workaround by removing or editing the autocorrect entry for :10:
:11: and :12:

Found in the Tools -> Autocorrect -> AutoCorrect Options dialog on the
Replace tab.

Stuart