Bugs:
- selecting history while showing index can cause segfault;
  index can also be invoked while in history, so far without problems;
  probably best to just not support this type of interaction, or implement
  proper mode transitions
- after moving around for a while, current sheet seems to get somehow separated
  from current list. This causes the "go up" box to disappear and the sheet
  number shown on hover becomes -1. This happens rarely, cause still unknown.
  No other problems were observed. "Home" usually solves this.

Parsing and input processing:
- unify alignment, direction
- on parse error, politely complain, don't terminate [almost there]
- convert assert(0) to proper error indications (BUG or such)
- quoted strings can have embedded double quotes, with \" (see parse_field)
- check what happens with UTF-8 (c4puter/motherboard)
- track renames
- test immunity to deletions more thoroughly (top sheet, sub-sheet, library,
  component, project, page layout)
- implement related_other_repo
- when in related_same_repo, still handle symlinks in repo leading out to
  non-repo file
- likewise, symlinks leading to other repo
- check if dir/subsheet-1 includes further subsheets from ./ or from dir/
- likewise, does it affect component library search path ?
- when looking for a file, consider that it may have been deleted/moved, and
  then don't magically resurrect it from the repo
- seems that atoms in sexpr can contain \ -  rules not entirely clear
- text fields in header can contain newlines as \\n

Data model:
- implement destructors
- check for memory leaks
- sheets appearing multiple times are parsed anew each time. Should we try
  to combine them ?
- likewise, reuse sheets and libraries that are the same in the next/previous
  revision (according to their OID)

Visualization (dwg.c and such):
- glabel: build for "right" style, then rotate poly (like hlabel)
- show open pins / wires
- check remaining alignment / direction / rotation cases in switch statements
- support mirroring (and detect-complain if unexpected) [should be done now]
- should get rid of gfx_user()
- page layout: still doesn't expand all the %X formats (only %K missing now)
- page layout: text may contain newlines
- page layout: support maxheight and maxwidth

Rendering/Text:
- better text size guessing also for FIG
- consider switching to Hershey fonts (that's what eeschema uses, right ?)
  (goal: prevent font geometry from changing when scaling)
- ~ as overline (grep for ~ in out.fig) [ done for Cairo, FIG still missing ]
- maybe let user set PNG size [we have zoom level]

Rendering/Lines:
- support line thickness ?
- find out why in Cairo PDF non-dashed lines disappear if CAIRO_LINE_CAP_ROUND

Rendering/Other:
- diff area algorithm will fill anything resembling a closed path, no matter
  how little is inside (e.g., a changed large but empty rectangle will be
  filled)
- interaction with eda-tools/genkicat fails: catalog text is lost
- strings in page layout (included expanded) can contain newlines as \n

GUI:
- dragging can be slow. maybe reusing old content and only redrawing new
  will help ?
- highlight nets ?
- we use find_corresponding_sheet way too often. Consider changing curr_sheet
  to new_sheet and old_sheet.
- introduce location string, as command-line argument, e.g.,
  [top-sheet/]rev-old,rev-new[,x,y[,zoom]]
  or maybe (allowing for sheets from completely different sources):
  [revA]:[topA]:[sheetA][,[revB]:[topB]:[sheetB]][@x,y[,zoom]]
  [revA]:[topA]:[sheetA][,[revB]:[topB]:[sheetB]][@x,y[,radius]]
  shape: circle ? rectangle ?
- set/use location string via clipboard
- incremental search with / ? and maybe Ctrl-S and Ctrl-R
  https://www.gnu.org/software/emacs/manual/html_node/emacs/Repeat-Isearch.html#Repeat-Isearch
- allow changing font size
- maybe allow changing diff contrast
- define consistent concept for keybord shortcuts
- would be nice to be able to reload design without quit, restart
- would be nice to be able to invoke PDF viewer on data sheets
- if invoked without file name, eeshow should show file dialog

GUI/history
- should have quick way to show diff of a single commit
- in history, set font to non-bold if showing details
- add scrolling with keys to history
- add manual selection with Up/Down/Enter
- "what I am selecting" indication (color of frames of sheets in history)
  is not very clear.
- list expansion: Joerg suggested to add pop-up, offset to the right, and
  keep list items fixed

GUI/sheets:
- need a way to change new/old sheet association, in case automatic selection
  fails (reserved hotkeys: Left/Right)

GUI/glabels:
- maybe indicate how many times label is used on each sheet
- maybe indicate how it is used
- there can be "hanging" pop-ups, by design. See comment in
  gui/glabel.c:hover_glabel

GUI/index:
- needs keyboard shortcut to invoke
- add keyboard shortcuts (cursor, Enter)
- examine interaction with background, suppress conflicts
- show sheet numbers [now we have file names; check with paths, etc.]