(core) Fix undo error for automatically removed rows, especially in summary tables

Summary:
Fixes a bug noted here: https://grist.slack.com/archives/C069RUP71/p1662564341132349

This bug could happen quite easily as follows:

1. Have a formula in a summary table such as `$group.amount`. Typically there's also a `SUM` but that's not essential.
2. Find a group with nonzero values of `amount`.
3. Delete all rows in that group in the source table. Typically that just means one row in a lonely group.
4. The summary table row is automatically deleted.
5. Try to undo. This raises an error about trying to update a non-existent summary table row.

I tried to account for this undo problem in https://phab.getgrist.com/D3489 by not saving the updated value for `$group` when it was found to be empty. The reason this was insufficient is that `$group.amount` is immediately invalidated anyway when the source row(s) are deleted (I think because that's just how dependency relations involving references work) *and* the calculated value of `$group.amount` changes even if `$group` doesn't. For example, `$group.amount` may have previously been `[100, 200]`. After deleting the rows, `$group.amount` becomes `[0, 0]`. Keeping `$group` unchanged prevents `$group.amount` from just being `[]`, but deleting the source rows means that the amounts become the numeric default `0` which is still a change. This change in value is then noted which leads to saving an undo action to update the summary table record. All this happens in step 3 above, and the summary record is only deleted after that point.

This diff removes that special handling for `group` and instead adds a more general fix to `action_summary.py`. This inserts undo actions for deleted rows at the beginning of the undo list rather than at the end, which was already done for deleted tables and columns.

Test Plan: Python tests

Reviewers: dsagal

Reviewed By: dsagal

Subscribers: dsagal

Differential Revision: https://phab.getgrist.com/D3626

sandbox/grist/test_undo.py

@@ -1,6 +1,8 @@
 import re
 import test_engine
 import testsamples
+import testutil
+
 
 class TestUndo(test_engine.EngineTestCase):
   def test_bad_undo(self):
@@ -80,3 +82,43 @@ class TestUndo(test_engine.EngineTestCase):
       [3,   "Address", [21]],
       [4,   "Table1", [22, 23]],
     ])
+
+  @test_engine.test_undo
+  def test_auto_remove_undo(self):
+    """
+    Test that a formula using docmodel.setAutoRemove doesn't break when undoing.
+    We don't actually recommend using docmodel.setAutoRemove in formulas,
+    but it'd be nice, and this is really testing that a bugfix about summary tables
+    also helps outside of summary tables.
+    """
+    self.load_sample(testutil.parse_test_sample({
+      "SCHEMA": [
+        [1, "Table", [
+          [11, "amount", "Numeric", False, "", "", ""],
+          [12, "amount2", "Numeric", True, "$amount", "", ""],
+          [13, "remove", "Any", True,
+           "table.table._engine.docmodel.setAutoRemove(rec, not $amount2)", "", ""],
+        ]]
+      ],
+      "DATA": {
+        "Table": [
+          ["id", "amount", "amount2"],
+          [21, 1, 1],
+          [22, 2, 2],
+        ]
+      }
+    }))
+    out_actions = self.update_record('Table', 21, amount=0)
+    self.assertOutActions(out_actions, {
+      'calc': [],
+      'direct': [True, False],
+      'stored': [['UpdateRecord', 'Table', 21, {'amount': 0.0}],
+                 ['RemoveRecord', 'Table', 21]],
+      'undo': [['UpdateRecord', 'Table', 21, {'amount2': 1.0}],
+               ['UpdateRecord', 'Table', 21, {'amount': 1.0}],
+               ['AddRecord', 'Table', 21, {}]],
+    })
+    self.assertTableData('Table', cols="subset", data=[
+      ["id", "amount", "amount2"],
+      [22, 2, 2],
+    ])