While using Rockbox for a while on my 1st-gen iPod mini I noticed that
the first entry of a list sometimes displays a wrong character at the
18th column. For example, the ':' character would display as 'z', the
'-' character as 'm', 0x00 would display '@' and so on. Oddly enough
this only occurred when the scrollbar was enabled.
I figured that the call to `display->set_viewport(list_text_vp);` in the
for loop inside `list_draw(...)` causes this. Digging deeper I noticed
that in the `lcd-bitmap-common.c` driver the `current_viewport` was
pointing to the start of the line's text. From what I can tell the
cause of this was that the viewport was set to a struct with a shorter
scope than the entire function.
The actual fix for this is quite straightforward -- once the scrollbar
has been drawn the viewport is now changed back to the default one.
Change-Id: Id6a7bd8f74864641ea1670fedea9d12d764e78c0
512be370c6