cli: don't lose short runs of context lines in diffs
If the context was 3 lines or less, it would get lost before this
patch.
@@ -697,7 +697,7 @@ fn print_diff(left: &[u8], right: &[u8], styler: &mut dyn Styler) {
}
}
} else {
- if context_before {
+ if context_before || context.len() < num_context_lines {
for line in &context {
print_diff_line(styler, line);
}
