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, 23 insertions, 0 deletions

diff --git a/third_party/git/t/perf/p5303-many-packs.sh b/third_party/git/t/perf/p5303-many-packs.sh
index 377985194116..f4c2ab058470 100755
--- a/third_party/git/t/perf/p5303-many-packs.sh
+++ b/third_party/git/t/perf/p5303-many-packs.sh
@@ -73,10 +73,15 @@ do
 		git rev-list --objects --all >/dev/null
 	'
 
+	test_perf "abbrev-commit ($nr_packs)" '
+		git rev-list --abbrev-commit HEAD >/dev/null
+	'
+
 	# This simulates the interesting part of the repack, which is the
 	# actual pack generation, without smudging the on-disk setup
 	# between trials.
 	test_perf "repack ($nr_packs)" '
+		GIT_TEST_FULL_IN_PACK_ARRAY=1 \
 		git pack-objects --keep-true-parents \
 		  --honor-pack-keep --non-empty --all \
 		  --reflog --indexed-objects --delta-base-offset \
@@ -84,4 +89,22 @@ do
 	'
 done
 
+# Measure pack loading with 10,000 packs.
+test_expect_success 'generate lots of packs' '
+	for i in $(test_seq 10000); do
+		echo "blob"
+		echo "data <<EOF"
+		echo "blob $i"
+		echo "EOF"
+		echo "checkpoint"
+	done |
+	git -c fastimport.unpackLimit=0 fast-import
+'
+
+# The purpose of this test is to evaluate load time for a large number
+# of packs while doing as little other work as possible.
+test_perf "load 10,000 packs" '
+	git rev-parse --verify "HEAD^{commit}"
+'
+
 test_done