By using one letter for the path type before and one letter for path
type after, we can encode much more information than just the current
'M'/'A'/'R'. In particular, we can indicate new and resolved
conflicts. The color still encodes the same information as before. The
output looks a bit weird after many years of using `hg status`. It's a
bit more similar to the `git status -s` format with one letter for the
index and one with the working copy. Will we get used to it and find
it useful?
This allows us to use "if(description,)" to test empty description. And
I think this change is unavoidable if we want to add support for commit
template.
"jj log -p --summary" now shows summary and color-words diff, like
"hg log -p --stat".
Handling of "-p" is tricky. I first considered "-p" would turn on the default
diff output, but I found it would be confusing if "jj log -p --git" showed
both color-words and git diffs. So the default format is inserted only if
no --git nor --color-words is explicitly specified.
The number of lines in the diff output is unchanged.
This makes diffs a little more readable when the "..." would otherwise hide a
single line of code that helps in understanding the surrounding context lines.
This change mostly rearranges the loop that consumes the diff lines, so it can
buffer up to num_context_lines*2+1 lines instead of just num_context_lines.
There's a bit of extra code to handle times when a "..." replaces the last line
of a diff.
Note that `jj diff --git` is unchanged, and will still output `@@` lines that
replace a single line of context.
Let's acknowledge everyone's contributions by replacing "Google LLC"
in the copyright header by "The Jujutsu Authors". If I understand
correctly, it won't have any legal effect, but maybe it still helps
reduce concerns from contributors (though I haven't heard any
concerns).
Google employees can read about Google's policy at
go/releasing/contributions#copyright.
Since whitespace change is barely visible in color-words diff, I think it
would be too verbose to add "\ No newline at end of file" marker. Let's just
append missing newline to make the command output readable.
