Merge branch 'jk/add-i-diff-compact-heuristics' into maint

"git add -i/-p" learned to honor diff.compactionHeuristic
experimental knob, so that the user can work on the same hunk split
as "git diff" output.

* jk/add-i-diff-compact-heuristics:
  add--interactive: respect diff.compactionHeuristic

Author: gitster

git-add--interactive.perl

@@ -45,6 +45,7 @@
 my $normal_color = $repo->get_color("", "reset");
 
 my $diff_algorithm = $repo->config('diff.algorithm');
+my $diff_compaction_heuristic = $repo->config_bool('diff.compactionheuristic');
 my $diff_filter = $repo->config('interactive.difffilter');
 
 my $use_readkey = 0;
@@ -749,6 +750,9 @@ sub parse_diff {
 	if (defined $diff_algorithm) {
 		splice @diff_cmd, 1, 0, "--diff-algorithm=${diff_algorithm}";
 	}
+	if ($diff_compaction_heuristic) {
+		splice @diff_cmd, 1, 0, "--compaction-heuristic";
+	}
 	if (defined $patch_mode_revision) {
 		push @diff_cmd, get_diff_reference($patch_mode_revision);
 	}