better formatting for generator expressions (PY-6219)

python/src/com/jetbrains/python/formatter/PyBlock.java

@@ -183,7 +183,8 @@ public class PyBlock implements ASTBlock {
         childIndent = Indent.getNormalIndent();
       }
     }
-    else if (parentType == PyElementTypes.PARENTHESIZED_EXPRESSION && hasLineBreaksBefore(child, 1)) {
+    else if ((parentType == PyElementTypes.PARENTHESIZED_EXPRESSION || parentType == PyElementTypes.GENERATOR_EXPRESSION) &&
+             hasLineBreaksBefore(child, 1)) {
       childIndent = Indent.getNormalIndent();
     }
 

python/testData/formatter/indentInGenerator.py

@@ -0,0 +1,3 @@
+def dbl():
+    return (
+        (a, a) for a in [])

python/testData/formatter/indentInGenerator_after.py

@@ -0,0 +1,3 @@
+def dbl():
+    return (
+        (a, a) for a in [])

python/testSrc/com/jetbrains/python/PyFormatterTest.java

@@ -144,6 +144,10 @@ public class PyFormatterTest extends PyTestCase {
     doTest();
   }
 
+  public void testIndentInGenerator() {  // PY-6219
+    doTest();
+  }
+
   public void testPsiFormatting() { // IDEA-69724
     String initial =
       "def method_name(\n" +