Merge pull request #17052 from ccordoba12/reconfigure-client-on-kerne…

…l-restart

PR: Reconfigure client before a kernel restart (IPython console)

spyder/plugins/ipythonconsole/tests/test_ipythonconsole.py

@@ -43,6 +43,7 @@
 from spyder.plugins.help.utils.sphinxify import CSS_PATH
 from spyder.plugins.ipythonconsole.plugin import IPythonConsole
 from spyder.plugins.ipythonconsole.utils.style import create_style_class
+from spyder.plugins.ipythonconsole.widgets import ClientWidget
 from spyder.utils.programs import get_temp_dir
 from spyder.utils.conda import is_conda_env
 
@@ -1126,10 +1127,13 @@ def test_clear_and_reset_magics_dbg(ipyconsole, qtbot):
 
 
 @flaky(max_runs=3)
-def test_restart_kernel(ipyconsole, qtbot):
+def test_restart_kernel(ipyconsole, mocker, qtbot):
     """
     Test that kernel is restarted correctly
     """
+    # Mock method we want to check
+    mocker.patch.object(ClientWidget, "_show_mpl_backend_errors")
+
     shell = ipyconsole.get_current_shellwidget()
     qtbot.waitUntil(lambda: shell._prompt_html is not None, timeout=SHELL_TIMEOUT)
 
@@ -1145,6 +1149,10 @@ def test_restart_kernel(ipyconsole, qtbot):
     assert 'Restarting kernel...' in shell._control.toPlainText()
     assert not shell.is_defined('a')
 
+    # Check that we try to show Matplotlib backend errors at the beginning and
+    # after the restart.
+    assert ClientWidget._show_mpl_backend_errors.call_count == 2
+
 
 @flaky(max_runs=3)
 def test_load_kernel_file_from_id(ipyconsole, qtbot):

spyder/plugins/ipythonconsole/widgets/client.py

@@ -204,9 +204,10 @@ def __del__(self):
             self.restart_thread.wait()
 
     # ----- Private methods ---------------------------------------------------
-    def _before_prompt_is_ready(self):
-        """Configure shellwidget before kernel is connected."""
-        self._show_loading_page()
+    def _before_prompt_is_ready(self, show_loading_page=True):
+        """Configuration before kernel is connected."""
+        if show_loading_page:
+            self._show_loading_page()
         self.shellwidget.sig_prompt_ready.connect(
             self._when_prompt_is_ready)
         # If remote execution, the loading page should be hidden as well
@@ -636,6 +637,9 @@ def restart_kernel(self):
                 sw.kernel_manager.stop_restarter()
                 sw.kernel_manager.autorestart = False
 
+                # Reconfigure client before the new kernel is connected again.
+                self._before_prompt_is_ready(show_loading_page=False)
+
                 # Create and run restarting thread
                 if (self.restart_thread is not None
                         and self.restart_thread.isRunning()):

spyder/plugins/ipythonconsole/widgets/shell.py

@@ -25,7 +25,6 @@
     _, is_pynsist, running_in_mac_app, running_under_pytest)
 from spyder.py3compat import to_text_string
 from spyder.utils.palette import SpyderPalette
-from spyder.utils import encoding
 from spyder.utils.clipboard_helper import CLIPBOARD_HELPER
 from spyder.utils import syntaxhighlighters as sh
 from spyder.plugins.ipythonconsole.utils.style import (