t/lib-submodule-update: add test removing nested submodules

The previous commit fixed a bug with the (no submodule) -> (nested
submodules) transition for commands in the unpack-trees machinery.

Let's add a test for the reverse transition (going from nested
submodules to no submodule), as it is not being tested currently.

While at it, uniformize the capitalization in the list of tests.

Signed-off-by: Philippe Blain <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: phil-blain

t/lib-submodule-update.sh

@@ -297,7 +297,7 @@ test_submodule_content () {
 # - Directory containing tracked files replaced by submodule
 # - Submodule replaced by tracked files in directory
 # - Submodule replaced by tracked file with the same name
-# - tracked file replaced by submodule
+# - Tracked file replaced by submodule
 #
 # The default is that submodule contents aren't changed until "git submodule
 # update" is run. And even then that command doesn't delete the work tree of
@@ -621,12 +621,13 @@ test_submodule_forced_switch () {
 # - Directory containing tracked files replaced by submodule
 # - Submodule replaced by tracked files in directory
 # - Submodule replaced by tracked file with the same name
-# - tracked file replaced by submodule
+# - Tracked file replaced by submodule
 #
 # New test cases
 # - Removing a submodule with a git directory absorbs the submodules
 #   git directory first into the superproject.
 # - Switching from no submodule to nested submodules
+# - Switching from nested submodules to no submodule
 
 # Internal function; use test_submodule_switch_recursing_with_args() or
 # test_submodule_forced_switch_recursing_with_args() instead.
@@ -760,6 +761,21 @@ test_submodule_recursing_with_args_common() {
 		)
 	'
 
+	# Switching to a commit without nested submodules removes their worktrees
+	test_expect_success "$command: worktrees of nested submodules are removed" '
+		prolog &&
+		reset_work_tree_to_interested add_nested_sub &&
+		(
+			cd submodule_update &&
+			git branch -t no_submodule origin/no_submodule &&
+			$command no_submodule &&
+			test_superproject_content origin/no_submodule &&
+			! test_path_is_dir sub1 &&
+			test_must_fail git config -f .git/modules/sub1/config core.worktree &&
+			test_must_fail git config -f .git/modules/sub1/modules/sub2/config core.worktree
+		)
+	'
+
 	########################## Modified submodule #########################
 	# Updating a submodule sha1 updates the submodule's work tree
 	test_expect_success "$command: modified submodule updates submodule work tree" '