Welcome wizard: Fix changing the language causing a empty folder to be created. Fixes #1903825 [Calibre installer makes an extra library folder](https://bugs.launchpad.net/calibre/+bug/1903825)

src/calibre/gui2/wizard/__init__.py

@@ -9,7 +9,7 @@
 import os
 import re
 import traceback
-from contextlib import closing
+from contextlib import closing, suppress
 from PyQt5.Qt import (
     QAbstractListModel, QDir, QIcon, QItemSelection, QItemSelectionModel, Qt,
     QWizard, QWizardPage, pyqtSignal
@@ -655,6 +655,7 @@ class LibraryPage(QWizardPage, LibraryUI):
 
     def __init__(self):
         QWizardPage.__init__(self)
+        self.made_dirs = []
         self.initial_library_location = None
         self.setupUi(self)
         self.registerField('library_location', self.location)
@@ -664,6 +665,10 @@ def __init__(self):
         self.location.textChanged.connect(self.location_text_changed)
         self.set_move_lib_label_text()
 
+    def makedirs(self, x):
+        self.made_dirs.append(x)
+        os.makedirs(x)
+
     def location_text_changed(self, newtext):
         self.completeChanged.emit()
 
@@ -759,7 +764,7 @@ def change(self):
                     show=True)
             if not os.path.exists(x):
                 try:
-                    os.makedirs(x)
+                    self.makedirs(x)
                 except:
                     return error_dialog(self, _('Bad location'),
                             _('Failed to create a folder at %s')%x,
@@ -794,7 +799,7 @@ def set_initial_library_location(self):
             self.default_library_name = lp
             if not os.path.exists(lp):
                 try:
-                    os.makedirs(lp)
+                    self.makedirs(lp)
                 except:
                     traceback.print_exc()
                     try:
@@ -828,6 +833,10 @@ def commit(self):
                 os.rmdir(dln)
         except Exception:
             pass
+        # dont leave behind any empty dirs
+        for x in self.made_dirs:
+            with suppress(OSError):
+                os.rmdir(x)
         if not os.path.exists(newloc):
             os.makedirs(newloc)
         prefs['library_path'] = newloc