rename: Add error.CircularLoop

Adds error.CircularLoop to rename functions.

For POSIX systems: according to the man page for rename, "EINVAL The
old pathname names an ancestor directory of the new pathname, or either
pathname argument contains a final component that is dot or dot-dot."
The later is always programmer error, so returning error.CircularLoop
should always be correct.

For WASI systems: the error should be the same as POSIX. The
documentation for INVAL says "Invalid argument, similar to `EINVAL` in
POSIX." This holds true for wasmtime 33.0.0 on my system, however the
zig CI returns PERM, so the test is skipped on WASI.

For Windows systems: based on empirical testing, SHARING_VIOLATION is
returned on Windows 10 to indicate a circular loop. At some point on
Windows 11, INVALID_PARAMATER started being used.

Author: gooncreeper

lib/std/fs/test.zig

@@ -991,6 +991,33 @@ test "Dir.rename file <-> dir" {
     }.impl);
 }
 
+test "Dir.rename circular loop" {
+    // TODO: The CI fails with error.PermissionDenied
+    if (native_os == .wasi) return error.SkipZigTest;
+
+    try testWithAllSupportedPathTypes(struct {
+        fn impl(ctx: *TestContext) !void {
+            const parent_path = try ctx.transformPath("parent");
+            const subdir_path = try ctx.transformPath("parent/subdir");
+            try ctx.dir.makeDir(parent_path);
+            try testing.expectError(error.CircularLoop, ctx.dir.rename(parent_path, subdir_path));
+
+            if (ctx.path_type == .relative) {
+                var parent = try ctx.dir.openDir("parent", .{});
+                defer parent.close();
+                try testing.expectError(error.CircularLoop, parent.rename("../parent", "subdir"));
+            }
+
+            if (ctx.path_type == .absolute) {
+                try testing.expectError(error.CircularLoop, std.fs.renameAbsolute(
+                    parent_path,
+                    subdir_path,
+                ));
+            }
+        }
+    }.impl);
+}
+
 test "rename" {
     var tmp_dir1 = tmpDir(.{});
     defer tmp_dir1.cleanup();

lib/std/os/windows.zig

@@ -1121,7 +1121,12 @@ pub fn DeleteFile(sub_path_w: []const u16, options: DeleteFileOptions) DeleteFil
     }
 }
 
-pub const MoveFileError = error{ FileNotFound, AccessDenied, Unexpected };
+pub const MoveFileError = error{
+    FileNotFound,
+    AccessDenied,
+    CircularLoop,
+    Unexpected,
+};
 
 pub fn MoveFileEx(old_path: []const u8, new_path: []const u8, flags: DWORD) (MoveFileError || Wtf8ToPrefixedFileWError)!void {
     const old_path_w = try sliceToPrefixedFileW(null, old_path);
@@ -1134,6 +1139,9 @@ pub fn MoveFileExW(old_path: [*:0]const u16, new_path: [*:0]const u16, flags: DW
         switch (GetLastError()) {
             .FILE_NOT_FOUND => return error.FileNotFound,
             .ACCESS_DENIED => return error.AccessDenied,
+            .INVALID_PARAMETER,
+            .SHARING_VIOLATION, // This is returned before Windows 11
+            => return error.CircularLoop,
             else => |err| return unexpectedError(err),
         }
     }

lib/std/posix.zig

@@ -2599,6 +2599,7 @@ pub const RenameError = error{
     FileBusy,
     DiskQuota,
     IsDir,
+    CircularLoop,
     SymLinkLoop,
     LinkQuotaExceeded,
     NameTooLong,
@@ -2662,7 +2663,7 @@ pub fn renameZ(old_path: [*:0]const u8, new_path: [*:0]const u8) RenameError!voi
         .BUSY => return error.FileBusy,
         .DQUOT => return error.DiskQuota,
         .FAULT => unreachable,
-        .INVAL => unreachable,
+        .INVAL => return error.CircularLoop,
         .ISDIR => return error.IsDir,
         .LOOP => return error.SymLinkLoop,
         .MLINK => return error.LinkQuotaExceeded,
@@ -2725,7 +2726,7 @@ fn renameatWasi(old: RelativePathWasi, new: RelativePathWasi) RenameError!void {
         .BUSY => return error.FileBusy,
         .DQUOT => return error.DiskQuota,
         .FAULT => unreachable,
-        .INVAL => unreachable,
+        .INVAL => return error.CircularLoop,
         .ISDIR => return error.IsDir,
         .LOOP => return error.SymLinkLoop,
         .MLINK => return error.LinkQuotaExceeded,
@@ -2777,7 +2778,7 @@ pub fn renameatZ(
         .BUSY => return error.FileBusy,
         .DQUOT => return error.DiskQuota,
         .FAULT => unreachable,
-        .INVAL => unreachable,
+        .INVAL => return error.CircularLoop,
         .ISDIR => return error.IsDir,
         .LOOP => return error.SymLinkLoop,
         .MLINK => return error.LinkQuotaExceeded,
@@ -2891,7 +2892,6 @@ pub fn renameatW(
     switch (rc) {
         .SUCCESS => {},
         .INVALID_HANDLE => unreachable,
-        .INVALID_PARAMETER => unreachable,
         .OBJECT_PATH_SYNTAX_BAD => unreachable,
         .ACCESS_DENIED => return error.AccessDenied,
         .OBJECT_NAME_NOT_FOUND => return error.FileNotFound,
@@ -2901,6 +2901,9 @@ pub fn renameatW(
         .DIRECTORY_NOT_EMPTY => return error.PathAlreadyExists,
         .FILE_IS_A_DIRECTORY => return error.IsDir,
         .NOT_A_DIRECTORY => return error.NotDir,
+        .INVALID_PARAMETER,
+        .SHARING_VIOLATION, // This is returned before Windows 11
+        => return error.CircularLoop,
         else => return windows.unexpectedStatus(rc),
     }
 }

src/fmt.zig

@@ -222,6 +222,7 @@ const FmtError = error{
     NetNameDeleted,
     InvalidArgument,
     ProcessNotFound,
+    CircularLoop,
 } || fs.File.OpenError;
 
 fn fmtPath(fmt: *Fmt, file_path: []const u8, check_mode: bool, dir: fs.Dir, sub_path: []const u8) FmtError!void {