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, 21 insertions, 0 deletions

diff --git a/third_party/git/t/t2403-worktree-move.sh b/third_party/git/t/t2403-worktree-move.sh
index 939d18d728..a4e1a178e0 100755
--- a/third_party/git/t/t2403-worktree-move.sh
+++ b/third_party/git/t/t2403-worktree-move.sh
@@ -112,6 +112,27 @@ test_expect_success 'move locked worktree (force)' '
 	git worktree move --force --force flump ploof
 '
 
+test_expect_success 'refuse to move worktree atop existing path' '
+	>bobble &&
+	git worktree add --detach beeble &&
+	test_must_fail git worktree move beeble bobble
+'
+
+test_expect_success 'move atop existing but missing worktree' '
+	git worktree add --detach gnoo &&
+	git worktree add --detach pneu &&
+	rm -fr pneu &&
+	test_must_fail git worktree move gnoo pneu &&
+	git worktree move --force gnoo pneu &&
+
+	git worktree add --detach nu &&
+	git worktree lock nu &&
+	rm -fr nu &&
+	test_must_fail git worktree move pneu nu &&
+	test_must_fail git worktree --force move pneu nu &&
+	git worktree move --force --force pneu nu
+'
+
 test_expect_success 'move a repo with uninitialized submodule' '
 	git init withsub &&
 	(