branch/diff-word-wrap

TODO:

~~Remove display: inline-block from <ins> and <del> to get more consistent word-wrapping~~
Alternative approach to extend inline element background color to line-height: https://stackoverflow.com/a/56781592
~~Check in various browsers if overflow-x: hidden is necessary for .difftxt to truncate "unbreakable" text (i.e. long runs of spaces)~~
Check layout and side-effects of diffs for the following web UI pages:
/fileedit
/wikiedit
/wdiff
/setup_skinedit
Update skins with customizations to diff layout
Update list of built-in files if src/diff.js remains unused (run tools/makemake.tcl to regenerate the makefiles)

Extended TODO (in case the feature can go to trunk):

  ::before { content: attr(data-line-number); }
  ::before { content: attr(data-diff-mark); }

~~Enable column-wise text selection in side-by-side diffs (i.e. only left or right side)~~
https://stackoverflow.com/questions/6619805/select-text-in-a-column-of-an-html-table
Firefox has built-in support: press and hold Ctrl, then Left Click and drag to enable column selection
Find a way to make the word-wrapped diffs available in parallel to the scrolling diffs (if possible by simple CSS toggle, otherwise by separate HTML/CSS/JS)

Forum thread:

Examples from GitHub and GitLab:

Fossil SCM