This makes history searches case-insensitive, unless the search string
contains an uppercase character.
This is what vim calls "smartcase".
Fixes#7273.
Because TERM was set to something other than 'dumb', we were subject to
syntax highlighting and other interactive features that would affect the
output. In practice we were getting lucky timing-wise, but with upcoming
interactive changes syntax highlighting started to fail this test.
I really kinda hate how insistent clang-format is to have line
breaks *IFF THE LINE IS TOO LONG*.
Like... lemme just add a break if it looks better, will you?
But it is the style at this time, so we shall tie an onion to our
belt.
