drive: add --drive-fast-list-bug-fix to control ListR bug workaround

See: https://forum.rclone.org/t/how-to-list-empty-directories-recursively/40995/12

backend/drive/drive.go

@@ -598,6 +598,28 @@ resource key is not needed.
 `,
 			Advanced:  true,
 			Sensitive: true,
+		}, {
+			Name: "fast_list_bug_fix",
+			Help: `Work around a bug in Google Drive listing.
+
+Normally rclone will work around a bug in Google Drive when using
+--fast-list (ListR) where the search "(A in parents) or (B in
+parents)" returns nothing sometimes. See #3114, #4289 and
+https://issuetracker.google.com/issues/149522397
+
+Rclone detects this by finding no items in more than one directory
+when listing and retries them as lists of individual directories.
+
+This means that if you have a lot of empty directories rclone will end
+up listing them all individually and this can take many more API
+calls.
+
+This flag allows the work-around to be disabled. This is **not**
+recommended in normal use - only if you have a particular case you are
+having trouble with like many empty directories.
+`,
+			Advanced: true,
+			Default:  true,
 		}, {
 			Name:     config.ConfigEncoding,
 			Help:     config.ConfigEncodingHelp,
@@ -672,6 +694,7 @@ type Options struct {
 	SkipShortcuts             bool                 `config:"skip_shortcuts"`
 	SkipDanglingShortcuts     bool                 `config:"skip_dangling_shortcuts"`
 	ResourceKey               string               `config:"resource_key"`
+	FastListBugFix            bool                 `config:"fast_list_bug_fix"`
 	Enc                       encoder.MultiEncoder `config:"encoding"`
 	EnvAuth                   bool                 `config:"env_auth"`
 }
@@ -1891,7 +1914,7 @@ func (f *Fs) listRRunner(ctx context.Context, wg *sync.WaitGroup, in chan listRE
 		// drive where (A in parents) or (B in parents) returns nothing
 		// sometimes. See #3114, #4289 and
 		// https://issuetracker.google.com/issues/149522397
-		if len(dirs) > 1 && !foundItems {
+		if f.opt.FastListBugFix && len(dirs) > 1 && !foundItems {
 			if atomic.SwapInt32(&f.grouping, 1) != 1 {
 				fs.Debugf(f, "Disabling ListR to work around bug in drive as multi listing (%d) returned no entries", len(dirs))
 			}