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[PATCH 2/6] fetch: backfill tags before setting upstream

From
Patrick Steinhardt <ps@pks.im>
Date
Feb 11, 2022, 07:46 UTC
Message-ID
<64c94e7a28d83fbaa1b6308b034d07c7be10e767.1644565025.git.ps@pks.im>
In-Reply-To
<cover.1644565025.git.ps@pks.im>
The fetch code flow is a bit hard to understand right now:
    1. We optionally prune all references which have vanished on the
       remote side.
    2. We fetch and update all other references locally.
    3. We update the upstream branch in the gitconfig.
    4. We backfill tags pointing into the history we have just fetched.

It is quite confusing that we fetch objects and update references in both (2) and (4), which is further stressed by the point that we require a `skip` label which jumps from (3) to (4) in case we fail to update the gitconfig as expected.

Reorder the code to first update all local references, and only after we have done so update the upstream branch information. This improves the code flow and furthermore makes it easier to refactor the way we update references together.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
---
 builtin/fetch.c | 33 ++++++++++++++++-----------------
 1 file changed, 16 insertions(+), 17 deletions(-)
diff --git a/builtin/fetch.c b/builtin/fetch.c
index 5b3b18a72f..9c7e4f12cd 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -1536,7 +1536,7 @@ static void backfill_tags(struct transport *transport, struct ref *ref_map,
 static int do_fetch(struct transport *transport,
 		    struct refspec *rs)
 {
-	struct ref *ref_map;
+	struct ref *ref_map = NULL;
 	int autotags = (transport->remote->fetch_tags == 1);
 	int retcode = 0;
 	const struct ref *remote_refs;
@@ -1618,11 +1618,22 @@ static int do_fetch(struct transport *transport,
 		}
 	}
 	if (fetch_and_consume_refs(transport, ref_map, worktrees)) {
-		free_refs(ref_map);
 		retcode = 1;
 		goto cleanup;
 	}
 
+	/* if neither --no-tags nor --tags was specified, do automated tag
+	 * following ... */
+	if (tags == TAGS_DEFAULT && autotags) {
+		struct ref *tags_ref_map = NULL, **tail = &tags_ref_map;
+
+		find_non_local_tags(remote_refs, &tags_ref_map, &tail);
+		if (tags_ref_map)
+			backfill_tags(transport, tags_ref_map, worktrees);
+
+		free_refs(tags_ref_map);
+	}
+
 	if (set_upstream) {
 		struct branch *branch = branch_get("HEAD");
 		struct ref *rm;
@@ -1642,7 +1653,7 @@ static int do_fetch(struct transport *transport,
 			if (!rm->peer_ref) {
 				if (source_ref) {
 					warning(_("multiple branches detected, incompatible with --set-upstream"));
-					goto skip;
+					goto cleanup;
 				} else {
 					source_ref = rm;
 				}
@@ -1656,7 +1667,7 @@ static int do_fetch(struct transport *transport,
 				warning(_("could not set upstream of HEAD to '%s' from '%s' when "
 					  "it does not point to any branch."),
 					shortname, transport->remote->name);
-				goto skip;
+				goto cleanup;
 			}
 
 			if (!strcmp(source_ref->name, "HEAD") ||
@@ -1676,21 +1687,9 @@ static int do_fetch(struct transport *transport,
 				  "you need to specify exactly one branch with the --set-upstream option"));
 		}
 	}
-skip:
-	free_refs(ref_map);
-
-	/* if neither --no-tags nor --tags was specified, do automated tag
-	 * following ... */
-	if (tags == TAGS_DEFAULT && autotags) {
-		struct ref **tail = &ref_map;
-		ref_map = NULL;
-		find_non_local_tags(remote_refs, &ref_map, &tail);
-		if (ref_map)
-			backfill_tags(transport, ref_map, worktrees);
-		free_refs(ref_map);
-	}
 
 cleanup:
+	free_refs(ref_map);
 	free_worktrees(worktrees);
 	return retcode;
 }
-- 
2.35.1
Previous: Patrick SteinhardtNext: Christian Couder
Message 5 of 27 in “fetch: improve atomicity of `--atomic` flag”
  1. 0/6 fetch: improve atomicity of `--atomic` flagPatrick Steinhardt, Feb 11, 2022
  2. 1/6 fetch: increase test coverage of fetchesPatrick Steinhardt, Feb 11, 2022
  3. Christian CouderFeb 15, 2022
  4. Patrick SteinhardtFeb 17, 2022
  5. 2/6 fetch: backfill tags before setting upstreamPatrick Steinhardt, Feb 11, 2022
  6. Christian CouderFeb 15, 2022
  7. 3/6 fetch: control lifecycle of FETCH_HEAD in a single placePatrick Steinhardt, Feb 11, 2022
  8. Christian CouderFeb 15, 2022
  9. Patrick SteinhardtFeb 17, 2022
  10. 4/6 fetch: report errors when backfilling tags failsPatrick Steinhardt, Feb 11, 2022
  11. Christian CouderFeb 15, 2022
  12. Patrick SteinhardtFeb 17, 2022
  13. Patrick SteinhardtFeb 17, 2022
  14. Jonathan TanFeb 16, 2022
  15. Elijah NewrenFeb 17, 2022
  16. 5/6 fetch: make `--atomic` flag cover backfilling of tagsPatrick Steinhardt, Feb 11, 2022
  17. Christian CouderFeb 15, 2022
  18. Jonathan TanFeb 16, 2022
  19. Patrick SteinhardtFeb 17, 2022
  20. Elijah NewrenFeb 17, 2022
  21. Patrick SteinhardtFeb 17, 2022
  22. 6/6 fetch: make `--atomic` flag cover pruning of refsPatrick Steinhardt, Feb 11, 2022
  23. Christian CouderFeb 15, 2022
  24. Patrick SteinhardtFeb 17, 2022
  25. Jonathan TanFeb 16, 2022
  26. Elijah NewrenFeb 17, 2022
  27. Patrick SteinhardtFeb 17, 2022

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