There are two ways to jump to the editor on a specific line: pressing `e` in the
staging or patch building panels, or clicking on a hyperlink in a delta diff. In
both cases, this works perfectly in the unstaged changes view, but in other
views (either staged changes, or an older commit) it can often jump to the wrong
line; this happens when there are further changes to the file being viewed in
later commits or in unstaged changes.
This commit fixes this so that you end up on the right line in these cases.
In go 1.22, loop variables are redeclared with each iteration of the
loop, rather than simple updated on each iteration. This means that we
no longer need to manually redeclare variables when they're closed over
by a function.
There's a bug in LineNumberOfLine, but the existing test coverage doesn't catch
it, as the only test case for this was one where oldStart and newStart were the
same for all hunks. Add a test case where newStart is different for one of the
hunks; this demonstrates a bug, where all expected results from index 12 on are
off by one.
