As stated in bug 83527 comment 24, "there is small problem with the button when its on the left panes in impress and draw, as its off by 1 pixel and should be shifted right." screenshot - attachment 116167 [details]
Confirmed. For reproducers: you need to grab the sidebar pane while it is docked to the right and drag it to the left. You can't dock it to the left, if it is undocked. Win 7 Pro 64-bit Version: 5.1.0.0.alpha1+ Build ID: 80ec99db4325a439a8a3f1d420d0a80f8bf9c439 TinderBox: Win-x86@62-merge-TDF, Branch:MASTER, Time: 2015-06-16_00:00:20 Locale: fi-FI (fi_FI)
@Beluga: It is easily seen when opening impress and seeing the slide pane on the right. :D
*** This bug has been marked as a duplicate of bug 93309 ***