sequencer: use the "octopus" merge strategy without forking

This teaches the sequencer to invoke the "octopus" strategy with a
function call instead of forking.

Signed-off-by: Alban Gruin <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: agrn

sequencer.c

@@ -2013,6 +2013,9 @@ static int do_pick_commit(struct repository *r,
 		if (!strcmp(opts->strategy, "resolve")) {
 			repo_read_index(r);
 			res |= merge_strategies_resolve(r, common, oid_to_hex(&head), remotes);
+		} else if (!strcmp(opts->strategy, "octopus")) {
+			repo_read_index(r);
+			res |= merge_strategies_octopus(r, common, oid_to_hex(&head), remotes);
 		} else
 			res |= try_merge_command(r, opts->strategy,
 						 opts->xopts_nr, (const char **)opts->xopts,