report parsing error if no expression was found after * (PY-10177 part 1)

python/src/com/jetbrains/python/parsing/ExpressionParsing.java

@@ -772,6 +772,7 @@ public class ExpressionParsing extends Parsing {
       PsiBuilder.Marker starExpr = myBuilder.mark();
       nextToken();
       if (!parseBitwiseORExpression(isTargetExpression)) {
+        myBuilder.error(message("PARSE.expected.expression"));
         starExpr.drop();
         return false;
       }

python/testData/psi/LoneStar.py

@@ -0,0 +1 @@
+x = (*)

python/testData/psi/LoneStar.txt

@@ -0,0 +1,13 @@
+PyFile:LoneStar.py
+  PyAssignmentStatement
+    PyTargetExpression: x
+      PsiElement(Py:IDENTIFIER)('x')
+    PsiWhiteSpace(' ')
+    PsiElement(Py:EQ)('=')
+    PsiWhiteSpace(' ')
+    PyParenthesizedExpression
+      PsiElement(Py:LPAR)('(')
+      PsiElement(Py:MULT)('*')
+      PsiErrorElement:expression expected
+        <empty list>
+      PsiElement(Py:RPAR)(')')

python/testSrc/com/jetbrains/python/PythonParsingTest.java

@@ -398,6 +398,10 @@ public class PythonParsingTest extends ParsingTestCase {
     doTest();
   }
 
+  public void testLoneStar() {  // PY-10177
+    doTest();
+  }
+
   public void doTest(LanguageLevel languageLevel) {
     LanguageLevel prev = myLanguageLevel;
     myLanguageLevel = languageLevel;