rebase: use our standard error return value

Git uses −1 to signal an error. The builtin rebase converts these to
+1 all over the place using !! (presumably because the in the scripted
version an error was signalled by +1). This is confusing and clutters
the code, we only need to convert the value when the function returns.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/rebase.c

@@ -1575,7 +1575,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 			die(_("could not move back to %s"),
 			    oid_to_hex(&options.orig_head));
 		remove_branch_state(the_repository, 0);
-		ret = !!finish_rebase(&options);
+		ret = finish_rebase(&options);
 		goto cleanup;
 	}
 	case ACTION_QUIT: {
@@ -1584,11 +1584,11 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 			struct replay_opts replay = REPLAY_OPTS_INIT;
 
 			replay.action = REPLAY_INTERACTIVE_REBASE;
-			ret = !!sequencer_remove_state(&replay);
+			ret = sequencer_remove_state(&replay);
 		} else {
 			strbuf_reset(&buf);
 			strbuf_addstr(&buf, options.state_dir);
-			ret = !!remove_dir_recursively(&buf, 0);
+			ret = remove_dir_recursively(&buf, 0);
 			if (ret)
 				error(_("could not remove '%s'"),
 				       options.state_dir);
@@ -1960,7 +1960,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 
 	if (require_clean_work_tree(the_repository, "rebase",
 				    _("Please commit or stash them."), 1, 1)) {
-		ret = 1;
+		ret = -1;
 		goto cleanup;
 	}
 
@@ -1995,7 +1995,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 					       RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
 					       NULL, buf.buf,
 					       DEFAULT_REFLOG_ACTION) < 0) {
-					ret = !!error(_("could not switch to "
+					ret = error(_("could not switch to "
 							"%s"),
 						      options.switch_to);
 					goto cleanup;
@@ -2010,7 +2010,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 			else
 				printf(_("Current branch %s is up to date.\n"),
 				       branch_name);
-			ret = !!finish_rebase(&options);
+			ret = finish_rebase(&options);
 			goto cleanup;
 		} else if (!(options.flags & REBASE_NO_QUIET))
 			; /* be quiet */
@@ -2088,7 +2088,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 			   RESET_HEAD_REFS_ONLY, "HEAD", msg.buf,
 			   DEFAULT_REFLOG_ACTION);
 		strbuf_release(&msg);
-		ret = !!finish_rebase(&options);
+		ret = finish_rebase(&options);
 		goto cleanup;
 	}
 
@@ -2102,7 +2102,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 	options.revisions = revisions.buf;
 
 run_rebase:
-	ret = !!run_specific_rebase(&options, action);
+	ret = run_specific_rebase(&options, action);
 
 cleanup:
 	strbuf_release(&buf);
@@ -2113,5 +2113,5 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 	free(options.strategy);
 	strbuf_release(&options.git_format_patch_opt);
 	free(squash_onto_name);
-	return ret;
+	return !!ret;
 }