revert(3p/git): Revert merge of git upstream at v2.26.2

This causes cgit to serve error pages, which is undesirable.

This reverts commit 5229c9b232, reversing
changes made to f2b211131f.

third_party/git/t/t3030-merge-recursive.sh

@@ -452,34 +452,6 @@ test_expect_success 'merge-recursive d/f conflict result' '
 
 '
 
-test_expect_success SYMLINKS 'dir in working tree with symlink ancestor does not produce d/f conflict' '
-	git init sym &&
-	(
-		cd sym &&
-		ln -s . foo &&
-		mkdir bar &&
-		>bar/file &&
-		git add foo bar/file &&
-		git commit -m "foo symlink" &&
-
-		git checkout -b branch1 &&
-		git commit --allow-empty -m "empty commit" &&
-
-		git checkout master &&
-		git rm foo &&
-		mkdir foo &&
-		>foo/bar &&
-		git add foo/bar &&
-		git commit -m "replace foo symlink with real foo dir and foo/bar file" &&
-
-		git checkout branch1 &&
-
-		git cherry-pick master &&
-		test_path_is_dir foo &&
-		test_path_is_file foo/bar
-	)
-'
-
 test_expect_success 'reset and 3-way merge' '
 
 	git reset --hard "$c2" &&
@@ -604,7 +576,7 @@ test_expect_success 'merge removes empty directories' '
 	git commit -mremoved-d/e &&
 	git checkout master &&
 	git merge -s recursive rm &&
-	test_path_is_missing d
+	test_must_fail test -d d
 '
 
 test_expect_success 'merge-recursive simple w/submodule' '
@@ -695,22 +667,15 @@ test_expect_success 'merging with triple rename across D/F conflict' '
 test_expect_success 'merge-recursive remembers the names of all base trees' '
 	git reset --hard HEAD &&
 
-	# make the index match $c1 so that merge-recursive below does not
-	# fail early
-	git diff --binary HEAD $c1 -- | git apply --cached &&
-
 	# more trees than static slots used by oid_to_hex()
 	for commit in $c0 $c2 $c4 $c5 $c6 $c7
 	do
 		git rev-parse "$commit^{tree}"
 	done >trees &&
 
-	# ignore the return code; it only fails because the input is weird...
+	# ignore the return code -- it only fails because the input is weird
 	test_must_fail git -c merge.verbosity=5 merge-recursive $(cat trees) -- $c1 $c3 >out &&
 
-	# ...but make sure it fails in the expected way
-	test_i18ngrep CONFLICT.*rename/rename out &&
-
 	# merge-recursive prints in reverse order, but we do not care
 	sort <trees >expect &&
 	sed -n "s/^virtual //p" out | sort >actual &&