Created attachment 126113 [details] Press F2 on B2 Open the attached file, click on B2, then press F2. The number will be overwritten with a few digits. No idea where the come from; if I delete row 1, the problem won't be reproduced. Ubuntu 16.04 64-bit.
Created attachment 126115 [details] Overlapping text in B2 after pressing F2
Version: 5.3.0.0.alpha0+ Build ID: dc4797a79e3f465e1fa930be7c69d8ec7d91c15e CPU Threads: 2; OS Version: Linux 3.16; UI Render: default; Locale: en-US (en_US.UTF-8); Calc: group Can't reproduce. F2 just toggles edit mode so the underlying number to me looks like a "15" which would make sense given the value in the cell. If you could try daily that would be great: http://dev-builds.libreoffice.org/daily/
I reproduce. Arch Linux 64-bit, KDE Plasma 5 Version: 5.3.0.0.alpha0+ Build ID: ab1b351840160655a9f0caedbb35e9fdf203c5a0 CPU Threads: 8; OS Version: Linux 4.6; UI Render: default; Locale: fi-FI (fi_FI.UTF-8); Calc: group Built on July 16th 2016 64-bit, KDE Plasma 5 Build ID: 5.1.4.2 Arch Linux build-1 CPU Threads: 8; OS Version: Linux 4.6; UI Render: default; Locale: fi-FI (fi_FI.UTF-8)
Created attachment 126535 [details] Overlapping text in B2 after pressing F2, in LO Dev 5.2.1.0+ Reproduced in today's Dev. All I'm doing is pressing F2 and Esc repeatedly. Most of the time, there are display artifacts over the cell.
Problem still persists in latest 5.3.2. SAL_USE_VCLPLUGIN is kde4. When editing the cells in the initial viewport, it is fine. The moment the viewport has moved, e.g. scroll down or scroll right, the overlap text will appear when editing cell. When move back to initial viewport, it will work fine once again.
This report is older, but I will dupe to a slightly newer one as it has more information. *** This bug has been marked as a duplicate of bug 100925 ***