fixed PY-10296 Access to protected member should have different severity levels

python/src/com/jetbrains/python/inspections/PyProtectedMemberInspection.java

@@ -7,6 +7,7 @@ import com.intellij.psi.PsiElementVisitor;
 import com.intellij.psi.PsiReference;
 import com.intellij.psi.util.PsiTreeUtil;
 import com.jetbrains.python.PyBundle;
+import com.jetbrains.python.PyNames;
 import com.jetbrains.python.psi.PyClass;
 import com.jetbrains.python.psi.PyExpression;
 import com.jetbrains.python.psi.PyReferenceExpression;
@@ -46,7 +47,7 @@ public class PyProtectedMemberInspection extends PyInspection {
     @Override
     public void visitPyReferenceExpression(PyReferenceExpression node) {
       final PyExpression qualifier = node.getQualifier();
-      if (qualifier == null) return;
+      if (qualifier == null || PyNames.CANONICAL_SELF.equals(qualifier.getText())) return;
       final String name = node.getName();
       if (name != null && name.startsWith("_") && !name.startsWith("__") && !name.endsWith("__")) {
         final PyClass parentClass = PsiTreeUtil.getParentOfType(node, PyClass.class);

python/testData/inspections/PyProtectedMemberInspection/selfField.py

@@ -0,0 +1,3 @@
+class B:
+  def __call__(self, event):
+   self._call_on_plugins("foo")

python/testSrc/com/jetbrains/python/inspections/PyProtectedMemberInspectionTest.java

@@ -27,6 +27,10 @@ public class PyProtectedMemberInspectionTest extends PyTestCase {
     doTest();
   }
 
+  public void testSelfField() {
+    doTest();
+  }
+
   private void doTest() {
     myFixture.configureByFile("inspections/PyProtectedMemberInspection/" + getTestName(true) + ".py");
     myFixture.enableInspections(PyProtectedMemberInspection.class);