indent, rather than align, child expression of subscription expression (PY-8572)

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

@@ -200,6 +200,12 @@ public class PyBlock implements ASTBlock {
         childIndent = Indent.getNormalIndent();
       }
     }
+    else if (parentType == PyElementTypes.SUBSCRIPTION_EXPRESSION) {
+      PyExpression indexExpression = ((PySubscriptionExpression)_node.getPsi()).getIndexExpression();
+      if (indexExpression != null && child == indexExpression.getNode()) {
+        childIndent = Indent.getNormalIndent();
+      }
+    }
 
     if (isAfterStatementList(child) && !hasLineBreaksBefore(child, 2)) {  // maybe enter was pressed and cut us from a previous (nested) statement list
       childIndent = Indent.getNormalIndent();
@@ -279,6 +285,9 @@ public class PyBlock implements ASTBlock {
     if (_node.getElementType() == PyElementTypes.PARAMETER_LIST) {
       return myContext.getSettings().ALIGN_MULTILINE_PARAMETERS;
     }
+    if (_node.getElementType() == PyElementTypes.SUBSCRIPTION_EXPRESSION) {
+      return false;
+    }
     if (child.getElementType() == PyTokenTypes.COMMA) {
       return false;
     }

python/testData/formatter/indentInSlice.py

@@ -0,0 +1,4 @@
+if True:
+    if False:
+        if True:
+            returnData['error_text'] = "User with  " + email_address + " email address is already part of " + company.name

python/testData/formatter/indentInSlice_after.py

@@ -0,0 +1,5 @@
+if True:
+    if False:
+        if True:
+            returnData[
+                'error_text'] = "User with  " + email_address + " email address is already part of " + company.name

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

@@ -248,7 +248,13 @@ public class PyFormatterTest extends PyTestCase {
     settings().WRAP_LONG_LINES = false;
     doTest();
   }
-  
+
+  public void testIndentInSlice() {  // PY-8572
+    settings().RIGHT_MARGIN = 120;
+    settings().WRAP_LONG_LINES = false;
+    doTest();
+  }
+
   private void doTest() {
     myFixture.configureByFile("formatter/" + getTestName(true) + ".py");
     ApplicationManager.getApplication().runWriteAction(new Runnable() {