diff --git a/t/t1300-config.sh b/t/t1300-config.sh
index f4e2752134..31c3878687 100755
--- a/t/t1300-config.sh
+++ b/t/t1300-config.sh
@@ -1098,15 +1098,20 @@ test_expect_success SYMLINKS 'symlink to nonexistent configuration' '
 	test_must_fail git config --file=linktolinktonada --list
 '
 
-test_expect_success 'check split_cmdline return' "
-	git config alias.split-cmdline-fix 'echo \"' &&
-	test_must_fail git split-cmdline-fix &&
-	echo foo > foo &&
-	git add foo &&
-	git commit -m 'initial commit' &&
-	git config branch.main.mergeoptions 'echo \"' &&
-	test_must_fail git merge main
-"
+test_expect_success 'check split_cmdline return' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		git config alias.split-cmdline-fix "echo \"" &&
+		test_must_fail git split-cmdline-fix &&
+		echo foo >foo &&
+		git add foo &&
+		git commit -m "initial commit" &&
+		git config branch.main.mergeoptions "echo \"" &&
+		test_must_fail git merge main
+	)
+'
 
 test_expect_success 'git -c "key=value" support' '
 	cat >expect <<-\EOF &&
@@ -1157,10 +1162,16 @@ test_expect_success 'git -c works with aliases of builtins' '
 '
 
 test_expect_success 'aliases can be CamelCased' '
-	test_config alias.CamelCased "rev-parse HEAD" &&
-	git CamelCased >out &&
-	git rev-parse HEAD >expect &&
-	test_cmp expect out
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit A &&
+		git config alias.CamelCased "rev-parse HEAD" &&
+		git CamelCased >out &&
+		git rev-parse HEAD >expect &&
+		test_cmp expect out
+	)
 '
 
 test_expect_success 'git -c does not split values on equals' '
@@ -2009,11 +2020,11 @@ test_expect_success '--show-origin getting a single key' '
 '
 
 test_expect_success 'set up custom config file' '
-	CUSTOM_CONFIG_FILE="custom.conf" &&
-	cat >"$CUSTOM_CONFIG_FILE" <<-\EOF
+	cat >"custom.conf" <<-\EOF &&
 	[user]
 		custom = true
 	EOF
+	CUSTOM_CONFIG_FILE="$(test-tool path-utils real_path custom.conf)"
 '
 
 test_expect_success !MINGW 'set up custom config file with special name characters' '
@@ -2052,22 +2063,33 @@ test_expect_success '--show-origin stdin with file include' '
 '
 
 test_expect_success '--show-origin blob' '
-	blob=$(git hash-object -w "$CUSTOM_CONFIG_FILE") &&
-	cat >expect <<-EOF &&
-	blob:$blob	user.custom=true
-	EOF
-	git config --blob=$blob --show-origin --list >output &&
-	test_cmp expect output
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		blob=$(git hash-object -w "$CUSTOM_CONFIG_FILE") &&
+		cat >expect <<-EOF &&
+		blob:$blob	user.custom=true
+		EOF
+		git config --blob=$blob --show-origin --list >output &&
+		test_cmp expect output
+	)
 '
 
 test_expect_success '--show-origin blob ref' '
-	cat >expect <<-\EOF &&
-	blob:main:custom.conf	user.custom=true
-	EOF
-	git add "$CUSTOM_CONFIG_FILE" &&
-	git commit -m "new config file" &&
-	git config --blob=main:"$CUSTOM_CONFIG_FILE" --show-origin --list >output &&
-	test_cmp expect output
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		cat >expect <<-\EOF &&
+		blob:main:custom.conf	user.custom=true
+		EOF
+		cp "$CUSTOM_CONFIG_FILE" custom.conf &&
+		git add custom.conf &&
+		git commit -m "new config file" &&
+		git config --blob=main:custom.conf --show-origin --list >output &&
+		test_cmp expect output
+	)
 '
 
 test_expect_success '--show-origin with --default' '