[2.2.x] Fixed #31246 -- Fixed locking models in QuerySet.select_for_update(of=()) for related fields and parent link fields with multi-table inheritance.

Partly regression in 0107e3d1058f653f66032f7fd3a0bd61e96bf782.

Backport of 1712a76b9dfda1ef220395e62ea87079da8c9f6c from master.

1 files changed, 22 insertions, 15 deletions

diff --git a/django/db/models/sql/compiler.py b/django/db/models/sql/compiler.py
index 9e709d0f6e..e5c726676a 100644
--- a/django/db/models/sql/compiler.py
+++ b/django/db/models/sql/compiler.py
@@ -948,19 +948,34 @@ class SQLCompiler:
         the query.
         """
         def _get_parent_klass_info(klass_info):
-            return (
-                {
+            for parent_model, parent_link in klass_info['model']._meta.parents.items():
+                parent_list = parent_model._meta.get_parent_list()
+                yield {
                     'model': parent_model,
                     'field': parent_link,
                     'reverse': False,
                     'select_fields': [
                         select_index
                         for select_index in klass_info['select_fields']
-                        if self.select[select_index][0].target.model == parent_model
+                        # Selected columns from a model or its parents.
+                        if (
+                            self.select[select_index][0].target.model == parent_model or
+                            self.select[select_index][0].target.model in parent_list
+                        )
                     ],
                 }
-                for parent_model, parent_link in klass_info['model']._meta.parents.items()
-            )
+
+        def _get_first_selected_col_from_model(klass_info):
+            """
+            Find the first selected column from a model. If it doesn't exist,
+            don't lock a model.
+
+            select_fields is filled recursively, so it also contains fields
+            from the parent models.
+            """
+            for select_index in klass_info['select_fields']:
+                if self.select[select_index][0].target.model == klass_info['model']:
+                    return self.select[select_index][0]
 
         def _get_field_choices():
             """Yield all allowed field paths in breadth-first search order."""
@@ -989,14 +1004,7 @@ class SQLCompiler:
         for name in self.query.select_for_update_of:
             klass_info = self.klass_info
             if name == 'self':
-                # Find the first selected column from a base model. If it
-                # doesn't exist, don't lock a base model.
-                for select_index in klass_info['select_fields']:
-                    if self.select[select_index][0].target.model == klass_info['model']:
-                        col = self.select[select_index][0]
-                        break
-                else:
-                    col = None
+                col = _get_first_selected_col_from_model(klass_info)
             else:
                 for part in name.split(LOOKUP_SEP):
                     klass_infos = (
@@ -1016,8 +1024,7 @@ class SQLCompiler:
                 if klass_info is None:
                     invalid_names.append(name)
                     continue
-                select_index = klass_info['select_fields'][0]
-                col = self.select[select_index][0]
+                col = _get_first_selected_col_from_model(klass_info)
             if col is not None:
                 if self.connection.features.select_for_update_of_column:
                     result.append(self.compile(col)[0])