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[PATCH v2 11/11] receive-pack: avoid duplicates between our refs and alternates

From
Jeff King <peff@peff.net>
Date
Feb 8, 2017, 20:53 UTC
Message-ID
<20170208205319.6ebuwv23bqxjuktz@sigill.intra.peff.net>
In-Reply-To
<20170208205219.twgm5rggovqbepte@sigill.intra.peff.net>

We de-duplicate ".have" refs among themselves, but never check if they are duplicates of our local refs. It's not unreasonable that they would be if we are a "--shared" or "--reference" clone of a similar repository; we'd have all the same tags.

We can handle this by inserting our local refs into the oidset, but obviously not suppressing duplicates (since the refnames are important).

Note that this also switches the order in which we advertise refs, processing ours first and then any alternates. The order shouldn't matter (and arguably showing our refs first makes more sense).

Signed-off-by: Jeff King <peff@peff.net>
---
 builtin/receive-pack.c |  4 +++-
 t/t5400-send-pack.sh   | 38 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 41 insertions(+), 1 deletion(-)
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index c23b0cce8..9ed8fbbfa 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -268,6 +268,8 @@ static int show_ref_cb(const char *path_full, const struct object_id *oid,
 		if (oidset_insert(seen, oid))
 			return 0;
 		path = ".have";
+	} else {
+		oidset_insert(seen, oid);
 	}
 	show_ref(path, oid->hash);
 	return 0;
@@ -289,9 +291,9 @@ static void write_head_info(void)
 {
 	static struct oidset seen = OIDSET_INIT;
 
+	for_each_ref(show_ref_cb, &seen);
 	for_each_alternate_ref(show_one_alternate_ref, &seen);
 	oidset_clear(&seen);
-	for_each_ref(show_ref_cb, &seen);
 	if (!sent_capabilities)
 		show_ref("capabilities^{}", null_sha1);
 
diff --git a/t/t5400-send-pack.sh b/t/t5400-send-pack.sh
index 305ca7a93..3331e0f53 100755
--- a/t/t5400-send-pack.sh
+++ b/t/t5400-send-pack.sh
@@ -255,4 +255,42 @@ test_expect_success 'deny pushing to delete current branch' '
 	)
 '
 
+extract_ref_advertisement () {
+	perl -lne '
+		# \\ is there to skip capabilities after \0
+		/push< ([^\\]+)/ or next;
+		exit 0 if $1 eq "0000";
+		print $1;
+	'
+}
+
+test_expect_success 'receive-pack de-dupes .have lines' '
+	git init shared &&
+	git -C shared commit --allow-empty -m both &&
+	git clone -s shared fork &&
+	(
+		cd shared &&
+		git checkout -b only-shared &&
+		git commit --allow-empty -m only-shared &&
+		git update-ref refs/heads/foo HEAD
+	) &&
+
+	# Notable things in this expectation:
+	#  - local refs are not de-duped
+	#  - .have does not duplicate locals
+	#  - .have does not duplicate itself
+	local=$(git -C fork rev-parse HEAD) &&
+	shared=$(git -C shared rev-parse only-shared) &&
+	cat >expect <<-EOF &&
+	$local refs/heads/master
+	$local refs/remotes/origin/HEAD
+	$local refs/remotes/origin/master
+	$shared .have
+	EOF
+
+	GIT_TRACE_PACKET=$(pwd)/trace git push fork HEAD:foo &&
+	extract_ref_advertisement <trace >refs &&
+	test_cmp expect refs
+'
+
 test_done
-- 
2.12.0.rc0.371.ga6cf8653b
Previous: Jeff King
Message 48 of 48 in “reducing resource usage of for_each_alternate_ref”
  1. 0/12 reducing resource usage of for_each_alternate_refJeff King, Jan 24, 2017
  2. 01/12 for_each_alternate_ref: handle failure from real_pathdup()Jeff King, Jan 24, 2017
  3. Junio C HamanoJan 25, 2017
  4. 02/12 for_each_alternate_ref: stop trimming trailing slashesJeff King, Jan 24, 2017
  5. 03/12 for_each_alternate_ref: use strbuf for path allocationJeff King, Jan 24, 2017
  6. Junio C HamanoJan 25, 2017
  7. Jeff KingJan 25, 2017
  8. 04/12 for_each_alternate_ref: pass name/oid instead of ref structJeff King, Jan 24, 2017
  9. 05/12 for_each_alternate_ref: replace transport code with for-each-refJeff King, Jan 24, 2017
  10. Junio C HamanoJan 25, 2017
  11. 06/12 clone: disable save_commit_bufferJeff King, Jan 24, 2017
  12. Junio C HamanoJan 25, 2017
  13. Jeff KingJan 25, 2017
  14. Jeff KingJan 25, 2017
  15. Jeff KingJan 25, 2017
  16. 07/12 fetch-pack: cache results of for_each_alternate_refJeff King, Jan 24, 2017
  17. Junio C HamanoJan 25, 2017
  18. Jeff KingJan 25, 2017
  19. 08/12 add oidset APIJeff King, Jan 24, 2017
  20. Ramsay JonesJan 24, 2017
  21. Jeff KingJan 24, 2017
  22. 10/12 receive-pack: fix misleading namespace/.have commentJeff King, Jan 24, 2017
  23. 09/12 receive-pack: use oidset to de-duplicate .have linesJeff King, Jan 24, 2017
  24. Junio C HamanoJan 25, 2017
  25. Jeff KingJan 25, 2017
  26. 12/12 receive-pack: avoid duplicates between our refs and alternatesJeff King, Jan 24, 2017
  27. Junio C HamanoJan 25, 2017
  28. Jeff KingJan 25, 2017
  29. 11/12 receive-pack: treat namespace .have lines like alternatesJeff King, Jan 24, 2017
  30. Junio C HamanoJan 25, 2017
  31. Jeff KingJan 25, 2017
  32. Lukas FleischerJan 27, 2017
  33. Jeff KingJan 27, 2017
  34. Junio C HamanoJan 27, 2017
  35. Brandon WilliamsJan 24, 2017
  36. Jeff KingJan 24, 2017
  37. 0/11 reducing resource usage of for_each_alternate_refJeff King, Feb 8, 2017
  38. 01/11 for_each_alternate_ref: handle failure from real_pathdup()Jeff King, Feb 8, 2017
  39. 02/11 for_each_alternate_ref: stop trimming trailing slashesJeff King, Feb 8, 2017
  40. 04/11 for_each_alternate_ref: pass name/oid instead of ref structJeff King, Feb 8, 2017
  41. 03/11 for_each_alternate_ref: use strbuf for path allocationJeff King, Feb 8, 2017
  42. 05/11 for_each_alternate_ref: replace transport code with for-each-refJeff King, Feb 8, 2017
  43. 08/11 receive-pack: use oidset to de-duplicate .have linesJeff King, Feb 8, 2017
  44. 07/11 add oidset APIJeff King, Feb 8, 2017
  45. 06/11 fetch-pack: cache results of for_each_alternate_refJeff King, Feb 8, 2017
  46. 09/11 receive-pack: fix misleading namespace/.have commentJeff King, Feb 8, 2017
  47. 10/11 receive-pack: treat namespace .have lines like alternatesJeff King, Feb 8, 2017
  48. 11/11 receive-pack: avoid duplicates between our refs and alternatesJeff King, Feb 8, 2017

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