[tvOS] Environment.GetSpecialFolder is too eager in creating the special directories

[filipnavara]

PR #57508 added the following code:

runtime/src/mono/System.Private.CoreLib/src/System/Environment.iOS.cs

Lines 102 to 111 in 98670d7

	#if TARGET_TVOS
	string? path = CombineSearchPath(NSSearchPathDirectory.NSLibraryDirectory, Path.Combine("Caches", "Documents", subdirectory));
	// Special version of CombineSearchPath which creates the path if needed.
	// This isn't needed for "real" search paths which always exist, but on tvOS
	// the base path is really a subdirectory we define rather than an OS directory.
	// In order to not treat Directory.Exists(SpecialFolder.ApplicationData) differently
	// on tvOS, guarantee that it exists by creating it here
	if (!Directory.Exists (path))
	Directory.CreateDirectory (path);
	#else

While the intention to create ApplicationData directory is correct the implementation creates also any subdirectory as well which is different from what legacy Mono did and what iOS does.

The expected version of the code should be closer to

                string? path = CombineSearchPath(NSSearchPathDirectory.NSLibraryDirectory, Path.Combine("Caches", "Documents"));
                // Special version of CombineSearchPath which creates the path if needed.
                // This isn't needed for "real" search paths which always exist, but on tvOS
                // the base path is really a subdirectory we define rather than an OS directory.
                // In order to not treat Directory.Exists(SpecialFolder.ApplicationData) differently
                // on tvOS, guarantee that it exists by creating it here
                if (!Directory.Exists (path))
                    Directory.CreateDirectory (path);
                path = Path.Combine(path, subdirectory);

(ie. only create the base directory and then combine the paths)

Ref: xamarin/xamarin-macios#12640

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Issue Details

---

PR #57508 added the following code:

runtime/src/mono/System.Private.CoreLib/src/System/Environment.iOS.cs

Lines 102 to 111 in 98670d7

	#if TARGET_TVOS
	string? path = CombineSearchPath(NSSearchPathDirectory.NSLibraryDirectory, Path.Combine("Caches", "Documents", subdirectory));
	// Special version of CombineSearchPath which creates the path if needed.
	// This isn't needed for "real" search paths which always exist, but on tvOS
	// the base path is really a subdirectory we define rather than an OS directory.
	// In order to not treat Directory.Exists(SpecialFolder.ApplicationData) differently
	// on tvOS, guarantee that it exists by creating it here
	if (!Directory.Exists (path))
	Directory.CreateDirectory (path);
	#else

While the intention to create ApplicationData directory is correct the implementation creates also any subdirectory as well which is different from what legacy Mono did and what iOS does.

The expected version of the code should be closer to

                string? path = CombineSearchPath(NSSearchPathDirectory.NSLibraryDirectory, Path.Combine("Caches", "Documents"));
                // Special version of CombineSearchPath which creates the path if needed.
                // This isn't needed for "real" search paths which always exist, but on tvOS
                // the base path is really a subdirectory we define rather than an OS directory.
                // In order to not treat Directory.Exists(SpecialFolder.ApplicationData) differently
                // on tvOS, guarantee that it exists by creating it here
                if (!Directory.Exists (path))
                    Directory.CreateDirectory (path);
                path = Path.Combine(path, subdirectory);

(ie. only create the base directory and then combine the paths)

Ref: xamarin/xamarin-macios#12640

Author:	filipnavara
Assignees:	-
Labels:	area-System.IO, untriaged
Milestone:	-

[filipnavara]

cc @akoeplinger @directhex @steveisok