PY-31795 Don't suggest removing parentheses when there is no expression inside

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

@@ -82,8 +82,9 @@ public class PyRedundantParenthesesInspection extends PyInspection {
 
     @Override
     public void visitPyParenthesizedExpression(final PyParenthesizedExpression node) {
-      final PyExpression expression = node.getContainedExpression();
       if (node.textContains('\n')) return;
+      final PyExpression expression = node.getContainedExpression();
+      if (expression == null) return;
       final PyYieldExpression yieldExpression = PsiTreeUtil.getParentOfType(expression, PyYieldExpression.class, false);
       if (yieldExpression != null) return;
       if (expression instanceof PyTupleExpression && myIgnoreTupleInReturn) {

python/src/com/jetbrains/python/inspections/quickfix/RedundantParenthesesQuickFix.java

@@ -10,6 +10,7 @@ import com.intellij.psi.PsiElement;
 import com.intellij.psi.util.PsiTreeUtil;
 import com.jetbrains.python.PyBundle;
 import com.jetbrains.python.psi.*;
+import com.jetbrains.python.psi.impl.PyPsiUtils;
 import org.jetbrains.annotations.NotNull;
 
 /**
@@ -38,11 +39,9 @@ public class RedundantParenthesesQuickFix implements LocalQuickFix {
         }
       }
       else {
-        while (element instanceof PyParenthesizedExpression) {
-          PyExpression expression = ((PyParenthesizedExpression)element).getContainedExpression();
-          if (expression != null) {
-            element = element.replace(expression);
-          }
+        final PyExpression content = PyPsiUtils.flattenParens((PyParenthesizedExpression)element);
+        if (content != null) {
+          element.replace(content);
         }
       }
     }

python/testData/inspections/PyRedundantParenthesesInspection/SingleLeftParenthesis.py

@@ -0,0 +1 @@
+if <caret>(<EOLError descr="Indent expected"></EOLError><EOLError descr="')' expected"></EOLError>

python/testData/inspections/PyRedundantParenthesesInspection/SyntaxErrorInside.py

@@ -0,0 +1,7 @@
+
+def pycharm_hanger_method(a, b):
+    if(<error descr="Unexpected expression syntax">!m_<caret>isReverse</error>)<error descr="Colon expected">{
+        m_startPoint = startPoint
+    } else {
+        m_endPoint = startPoint
+    }</error>

python/testData/inspections/RedundantParenthesesMultipleParentheses.py

@@ -0,0 +1 @@
+(<caret>((42)))

python/testData/inspections/RedundantParenthesesMultipleParentheses_after.py

@@ -0,0 +1 @@
+(42)

python/testSrc/com/jetbrains/python/PyQuickFixTest.java

@@ -248,6 +248,10 @@ public class PyQuickFixTest extends PyTestCase {
     doInspectionTest(PyRedundantParenthesesInspection.class, PyBundle.message("QFIX.redundant.parentheses"), true, true);
   }
 
+  public void testRedundantParenthesesMultipleParentheses() {
+    doInspectionTest(PyRedundantParenthesesInspection.class, PyBundle.message("QFIX.redundant.parentheses"), true, true);
+  }
+
   // PY-15506
   public void testEmptyListOfBaseClasses() {
     doInspectionTest(PyRedundantParenthesesInspection.class, PyBundle.message("QFIX.redundant.parentheses"), true, true);

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

@@ -78,6 +78,16 @@ public class PyRedundantParenthesesInspectionTest extends PyInspectionTestCase {
     doTest();
   }
 
+  // PY-31795
+  public void testSyntaxErrorInside() {
+    doTest();
+  }
+
+  // PY-31795
+  public void testSingleLeftParenthesis() {
+    doTest();
+  }
+
   // PY-20324
   public void testReturn() {
     runWithLanguageLevel(LanguageLevel.PYTHON35, this::doTest);