merge(3p/git): Merge git subtree at v2.29.2 r/1890

This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb

1 files changed, 84 insertions, 5 deletions

diff --git a/third_party/git/t/t4067-diff-partial-clone.sh b/third_party/git/t/t4067-diff-partial-clone.sh
index 90c8fb2901..804f2a82e8 100755
--- a/third_party/git/t/t4067-diff-partial-clone.sh
+++ b/third_party/git/t/t4067-diff-partial-clone.sh
@@ -20,7 +20,7 @@ test_expect_success 'git show batches blobs' '
 	# Ensure that there is exactly 1 negotiation by checking that there is
 	# only 1 "done" line sent. ("done" marks the end of negotiation.)
 	GIT_TRACE_PACKET="$(pwd)/trace" git -C client show HEAD &&
-	grep "git> done" trace >done_lines &&
+	grep "fetch> done" trace >done_lines &&
 	test_line_count = 1 done_lines
 '
 
@@ -44,7 +44,7 @@ test_expect_success 'diff batches blobs' '
 	# Ensure that there is exactly 1 negotiation by checking that there is
 	# only 1 "done" line sent. ("done" marks the end of negotiation.)
 	GIT_TRACE_PACKET="$(pwd)/trace" git -C client diff HEAD^ HEAD &&
-	grep "git> done" trace >done_lines &&
+	grep "fetch> done" trace >done_lines &&
 	test_line_count = 1 done_lines
 '
 
@@ -75,6 +75,37 @@ test_expect_success 'diff skips same-OID blobs' '
 	! grep "want $(cat hash-b)" trace
 '
 
+test_expect_success 'when fetching missing objects, diff skips GITLINKs' '
+	test_when_finished "rm -rf sub server client trace" &&
+
+	test_create_repo sub &&
+	test_commit -C sub first &&
+
+	test_create_repo server &&
+	echo a >server/a &&
+	git -C server add a &&
+	git -C server submodule add "file://$(pwd)/sub" &&
+	git -C server commit -m x &&
+
+	test_commit -C server/sub second &&
+	echo another-a >server/a &&
+	git -C server add a sub &&
+	git -C server commit -m x &&
+
+	test_config -C server uploadpack.allowfilter 1 &&
+	test_config -C server uploadpack.allowanysha1inwant 1 &&
+	git clone --bare --filter=blob:limit=0 "file://$(pwd)/server" client &&
+
+	echo a | git hash-object --stdin >hash-old-a &&
+	echo another-a | git hash-object --stdin >hash-new-a &&
+
+	# Ensure that a and another-a are fetched, and check (by successful
+	# execution of the diff) that no invalid OIDs are sent.
+	GIT_TRACE_PACKET="$(pwd)/trace" git -C client diff HEAD^ HEAD &&
+	grep "want $(cat hash-old-a)" trace &&
+	grep "want $(cat hash-new-a)" trace
+'
+
 test_expect_success 'diff with rename detection batches blobs' '
 	test_when_finished "rm -rf server client trace" &&
 
@@ -94,9 +125,57 @@ test_expect_success 'diff with rename detection batches blobs' '
 
 	# Ensure that there is exactly 1 negotiation by checking that there is
 	# only 1 "done" line sent. ("done" marks the end of negotiation.)
-	GIT_TRACE_PACKET="$(pwd)/trace" git -C client diff -M HEAD^ HEAD >out &&
-	grep "similarity index" out &&
-	grep "git> done" trace >done_lines &&
+	GIT_TRACE_PACKET="$(pwd)/trace" git -C client diff --raw -M HEAD^ HEAD >out &&
+	grep ":100644 100644.*R[0-9][0-9][0-9].*b.*c" out &&
+	grep "fetch> done" trace >done_lines &&
+	test_line_count = 1 done_lines
+'
+
+test_expect_success 'diff does not fetch anything if inexact rename detection is not needed' '
+	test_when_finished "rm -rf server client trace" &&
+
+	test_create_repo server &&
+	echo a >server/a &&
+	printf "b\nb\nb\nb\nb\n" >server/b &&
+	git -C server add a b &&
+	git -C server commit -m x &&
+	mv server/b server/c &&
+	git -C server add c &&
+	git -C server commit -a -m x &&
+
+	test_config -C server uploadpack.allowfilter 1 &&
+	test_config -C server uploadpack.allowanysha1inwant 1 &&
+	git clone --bare --filter=blob:limit=0 "file://$(pwd)/server" client &&
+
+	# Ensure no fetches.
+	GIT_TRACE_PACKET="$(pwd)/trace" git -C client diff --raw -M HEAD^ HEAD &&
+	! test_path_exists trace
+'
+
+test_expect_success 'diff --break-rewrites fetches only if necessary, and batches blobs if it does' '
+	test_when_finished "rm -rf server client trace" &&
+
+	test_create_repo server &&
+	echo a >server/a &&
+	printf "b\nb\nb\nb\nb\n" >server/b &&
+	git -C server add a b &&
+	git -C server commit -m x &&
+	printf "c\nc\nc\nc\nc\n" >server/b &&
+	git -C server commit -a -m x &&
+
+	test_config -C server uploadpack.allowfilter 1 &&
+	test_config -C server uploadpack.allowanysha1inwant 1 &&
+	git clone --bare --filter=blob:limit=0 "file://$(pwd)/server" client &&
+
+	# Ensure no fetches.
+	GIT_TRACE_PACKET="$(pwd)/trace" git -C client diff --raw -M HEAD^ HEAD &&
+	! test_path_exists trace &&
+
+	# But with --break-rewrites, ensure that there is exactly 1 negotiation
+	# by checking that there is only 1 "done" line sent. ("done" marks the
+	# end of negotiation.)
+	GIT_TRACE_PACKET="$(pwd)/trace" git -C client diff --break-rewrites --raw -M HEAD^ HEAD &&
+	grep "fetch> done" trace >done_lines &&
 	test_line_count = 1 done_lines
 '