bpo-38183: Test_idle ignores user config directory GH-16198)

It no longer tries to create or access .idlerc or any files within.
Users must run IDLE to discover problems with saving settings.

4 files changed, 42 insertions, 35 deletions

diff --git a/Lib/idlelib/config.py b/Lib/idlelib/config.py
index 683b000..12e6f9f 100644
--- a/Lib/idlelib/config.py
+++ b/Lib/idlelib/config.py
@@ -130,7 +130,7 @@ class IdleUserConfParser(IdleConfParser):
         to disk. Otherwise, remove the file from disk if it exists.
         """
         fname = self.file
-        if fname:
+        if fname and fname[0] != '#':
             if not self.IsEmpty():
                 try:
                     cfgFile = open(fname, 'w')
@@ -166,12 +166,12 @@ class IdleConf:
     def CreateConfigHandlers(self):
         "Populate default and user config parser dictionaries."
         idledir = os.path.dirname(__file__)
-        self.userdir = userdir = self.GetUserCfgDir()
+        self.userdir = userdir = '' if idlelib.testing else self.GetUserCfgDir()
         for cfg_type in self.config_types:
             self.defaultCfg[cfg_type] = IdleConfParser(
                 os.path.join(idledir, f'config-{cfg_type}.def'))
             self.userCfg[cfg_type] = IdleUserConfParser(
-                os.path.join(userdir, f'config-{cfg_type}.cfg'))
+                os.path.join(userdir or '#', f'config-{cfg_type}.cfg'))
 
     def GetUserCfgDir(self):
         """Return a filesystem directory for storing user config files.
@@ -182,12 +182,13 @@ class IdleConf:
         userDir = os.path.expanduser('~')
         if userDir != '~': # expanduser() found user home dir
             if not os.path.exists(userDir):
-                warn = ('\n Warning: os.path.expanduser("~") points to\n ' +
-                        userDir + ',\n but the path does not exist.')
-                try:
-                    print(warn, file=sys.stderr)
-                except OSError:
-                    pass
+                if not idlelib.testing:
+                    warn = ('\n Warning: os.path.expanduser("~") points to\n ' +
+                            userDir + ',\n but the path does not exist.')
+                    try:
+                        print(warn, file=sys.stderr)
+                    except OSError:
+                        pass
                 userDir = '~'
         if userDir == "~": # still no path to home!
             # traditionally IDLE has defaulted to os.getcwd(), is this adequate?
@@ -197,10 +198,13 @@ class IdleConf:
             try:
                 os.mkdir(userDir)
             except OSError:
-                warn = ('\n Warning: unable to create user config directory\n' +
-                        userDir + '\n Check path and permissions.\n Exiting!\n')
                 if not idlelib.testing:
-                    print(warn, file=sys.stderr)
+                    warn = ('\n Warning: unable to create user config directory\n' +
+                            userDir + '\n Check path and permissions.\n Exiting!\n')
+                    try:
+                        print(warn, file=sys.stderr)
+                    except OSError:
+                        pass
                 raise SystemExit
         # TODO continue without userDIr instead of exit
         return userDir
diff --git a/Lib/idlelib/editor.py b/Lib/idlelib/editor.py
index 5cbf704..838cb04 100644
--- a/Lib/idlelib/editor.py
+++ b/Lib/idlelib/editor.py
@@ -116,7 +116,7 @@ class EditorWindow(object):
             self.tkinter_vars = {}  # keys: Tkinter event names
                                     # values: Tkinter variable instances
             self.top.instance_dict = {}
-        self.recent_files_path = os.path.join(
+        self.recent_files_path = idleConf.userdir and os.path.join(
                 idleConf.userdir, 'recent-files.lst')
 
         self.prompt_last_line = ''  # Override in PyShell
@@ -924,9 +924,11 @@ class EditorWindow(object):
 
     def update_recent_files_list(self, new_file=None):
         "Load and update the recent files list and menus"
+        # TODO: move to iomenu.
         rf_list = []
-        if os.path.exists(self.recent_files_path):
-            with open(self.recent_files_path, 'r',
+        file_path = self.recent_files_path
+        if file_path and os.path.exists(file_path):
+            with open(file_path, 'r',
                       encoding='utf_8', errors='replace') as rf_list_file:
                 rf_list = rf_list_file.readlines()
         if new_file:
@@ -942,19 +944,19 @@ class EditorWindow(object):
         rf_list = [path for path in rf_list if path not in bad_paths]
         ulchars = "1234567890ABCDEFGHIJK"
         rf_list = rf_list[0:len(ulchars)]
-        try:
-            with open(self.recent_files_path, 'w',
-                        encoding='utf_8', errors='replace') as rf_file:
-                rf_file.writelines(rf_list)
-        except OSError as err:
-            if not getattr(self.root, "recentfilelist_error_displayed", False):
-                self.root.recentfilelist_error_displayed = True
-                tkMessageBox.showwarning(title='IDLE Warning',
-                    message="Cannot update File menu Recent Files list. "
-                            "Your operating system says:\n%s\n"
-                            "Select OK and IDLE will continue without updating."
-                        % self._filename_to_unicode(str(err)),
-                    parent=self.text)
+        if file_path:
+            try:
+                with open(file_path, 'w',
+                          encoding='utf_8', errors='replace') as rf_file:
+                    rf_file.writelines(rf_list)
+            except OSError as err:
+                if not getattr(self.root, "recentfiles_message", False):
+                    self.root.recentfiles_message = True
+                    tkMessageBox.showwarning(title='IDLE Warning',
+                        message="Cannot save Recent Files list to disk.\n"
+                                f"  {err}\n"
+                                "Select OK to continue.",
+                        parent=self.text)
         # for each edit window instance, construct the recent files menu
         for instance in self.top.instance_dict:
             menu = instance.recent_files_menu
diff --git a/Lib/idlelib/idle_test/test_config.py b/Lib/idlelib/idle_test/test_config.py
index 492f2f6..697fda5 100644
--- a/Lib/idlelib/idle_test/test_config.py
+++ b/Lib/idlelib/idle_test/test_config.py
@@ -220,7 +220,7 @@ class IdleConfTest(unittest.TestCase):
 
     @unittest.skipIf(sys.platform.startswith('win'), 'this is test for unix system')
     def test_get_user_cfg_dir_unix(self):
-        "Test to get user config directory under unix"
+        # Test to get user config directory under unix.
         conf = self.new_config(_utest=True)
 
         # Check normal way should success
@@ -243,7 +243,7 @@ class IdleConfTest(unittest.TestCase):
 
     @unittest.skipIf(not sys.platform.startswith('win'), 'this is test for Windows system')
     def test_get_user_cfg_dir_windows(self):
-        "Test to get user config directory under Windows"
+        # Test to get user config directory under Windows.
         conf = self.new_config(_utest=True)
 
         # Check normal way should success
@@ -284,12 +284,12 @@ class IdleConfTest(unittest.TestCase):
             self.assertIsInstance(user_parser, config.IdleUserConfParser)
 
         # Check config path are correct
-        for config_type, parser in conf.defaultCfg.items():
+        for cfg_type, parser in conf.defaultCfg.items():
             self.assertEqual(parser.file,
-                             os.path.join(idle_dir, 'config-%s.def' % config_type))
-        for config_type, parser in conf.userCfg.items():
+                             os.path.join(idle_dir, f'config-{cfg_type}.def'))
+        for cfg_type, parser in conf.userCfg.items():
             self.assertEqual(parser.file,
-                             os.path.join(conf.userdir, 'config-%s.cfg' % config_type))
+                             os.path.join(conf.userdir or '#', f'config-{cfg_type}.cfg'))
 
     def test_load_cfg_files(self):
         conf = self.new_config(_utest=True)
@@ -373,7 +373,7 @@ class IdleConfTest(unittest.TestCase):
                                                        'background': '#171717'})
 
     def test_get_theme_dict(self):
-        "XXX: NOT YET DONE"
+        # TODO: finish.
         conf = self.mock_config()
 
         # These two should be the same
diff --git a/Lib/idlelib/pyshell.py b/Lib/idlelib/pyshell.py
index 08716a9..2e4dfad 100755
--- a/Lib/idlelib/pyshell.py
+++ b/Lib/idlelib/pyshell.py
@@ -133,6 +133,7 @@ class PyShellEditorWindow(EditorWindow):
         self.text.bind("<<clear-breakpoint-here>>", self.clear_breakpoint_here)
         self.text.bind("<<open-python-shell>>", self.flist.open_shell)
 
+        #TODO: don't read/write this from/to .idlerc when testing
         self.breakpointPath = os.path.join(
                 idleConf.userdir, 'breakpoints.lst')
         # whenever a file is changed, restore breakpoints