Fix 6.x regression when using fts::index and certain inheritance patterns

In #7743, we moved `fts` and some other modules underneath `std`.
Unfortunately, index names are not properly normalized to refer to
them as such, and so FTS indexes specified as `fts::index` would
typically have `fts::index` as their shortname. This is wrong in
general, and also specifically wrong since some code paths *do*
produce normalized names, causing breakages.

Fix it by normalizing the name.

I did some testing, and this should be backportable if we use
`schema-repair`. I hate `schema-repair` but I think it is safer than
some of the non-repair ideas I had, like trying to ignore this
particular name difference.

Fixes #8465

Author: msullivan

edb/schema/indexes.py

@@ -102,9 +102,9 @@ def is_index_supporting_tuples(
         "std::fts::index",
         "ext::pg_trgm::gin",
         "ext::pg_trgm::gist",
-        "pg::gist",
-        "pg::gin",
-        "pg::brin",
+        "std::pg::gist",
+        "std::pg::gin",
+        "std::pg::brin",
     }
 
 
@@ -577,9 +577,18 @@ def _classname_from_ast(
     ) -> sn.QualName:
         # We actually want to override how ReferencedObjectCommand determines
         # the classname
-        shortname = super(
-            referencing.ReferencedObjectCommand, cls
-        )._classname_from_ast(schema, astnode, context)
+        #
+        # We need to resolve the name so that we get fully
+        # canonicalized names for things like fts::index, which are
+        # properly std::fts::index.
+        # (We have to do that ourselves here because we are skipping
+        # ReferencedObjectCommand, which would otherwise handle it.)
+        shortname = utils.resolve_name(
+            utils.ast_ref_to_name(astnode.name),
+            modaliases=context.modaliases,
+            schema=schema,
+            metaclass=cls.get_schema_metaclass(),
+        )
 
         referrer_ctx = cls.get_referrer_context(context)
         if referrer_ctx is not None:

tests/test_edgeql_data_migration.py

@@ -8361,6 +8361,31 @@ async def test_edgeql_migration_eq_index_04(self):
             }],
         )
 
+    async def test_edgeql_migration_eq_index_05(self):
+        await self.migrate('''
+            abstract type Named {
+                index fts::index on (
+                    std::fts::with_options(
+                        .name, language := std::fts::Language.eng));
+                required property name: std::str;
+            };
+        ''')
+
+        await self.start_migration('''
+            abstract type Named {
+                index std::fts::index on (
+                    std::fts::with_options(
+                        .name, language := std::fts::Language.eng));
+                required property name: std::str;
+            };
+        ''')
+
+        # no changes
+        await self.assert_describe_migration({
+            'confirmed': [],
+            'complete': True,
+        })
+
     async def test_edgeql_migration_eq_collections_01(self):
         await self.migrate(r"""
             type Base;

tests/test_edgeql_ddl.py

@@ -13565,6 +13565,34 @@ async def test_edgeql_ddl_index_09(self):
                 };
             """)
 
+    async def test_edgeql_ddl_index_fts_01(self):
+        await self.con.execute('''
+            CREATE ABSTRACT TYPE default::Named {
+                CREATE REQUIRED PROPERTY name: std::str;
+                CREATE INDEX fts::index ON (
+                  fts::with_options(.name, language := fts::Language.eng)
+                );
+            };
+
+            CREATE ABSTRACT TYPE default::Project EXTENDING default::Named
+            {
+                ALTER PROPERTY name {
+                    SET OWNED;
+                    CREATE CONSTRAINT std::exclusive;
+                };
+            };
+        ''')
+
+        # Names canonicalized as std::fts::index
+        await self.assert_query_result(
+            '''
+            select schema::Index { name }
+            filter exists .<indexes[is schema::ObjectType]
+            and .name like '%index';
+            ''',
+            [{"name": "std::fts::index"}, {"name": "std::fts::index"}]
+        )
+
     async def test_edgeql_ddl_abstract_index_01(self):
         for _ in range(2):
             await self.con.execute('''

tests/test_edgeql_explain.py

@@ -1374,7 +1374,7 @@ def get_gist_index_expected_res(self, fname, plan_type, message=None):
                                 'title': 'index_name',
                                 'type': 'index',
                                 'value':
-                                    f"index 'pg::gist' of object type "
+                                    f"index 'std::pg::gist' of object type "
                                     f"'default::RangeTest' on (.{fname})",
                             },
                             {
@@ -1410,7 +1410,7 @@ def get_gist_index_expected_res(self, fname, plan_type, message=None):
                                         'title': 'index_name',
                                         'type': 'index',
                                         'value':
-                                            f"index 'pg::gist' of object"
+                                            f"index 'std::pg::gist' of object"
                                             f" type 'default::RangeTest'"
                                             f" on (.{fname})",
                                     },
@@ -1897,7 +1897,7 @@ async def test_edgeql_explain_json_contains_01(self):
                                         'title': 'index_name',
                                         'type': 'index',
                                         'value':
-                                            f"index 'pg::gin' of object"
+                                            f"index 'std::pg::gin' of object"
                                             f" type 'default::JSONTest'"
                                             f" on (.val)",
                                     },

tests/test_indexes.py

@@ -295,7 +295,7 @@ async def test_index_08(self):
                 {
                     'indexes': [
                         {
-                            'name': 'fts::index',
+                            'name': 'std::fts::index',
                             'kwargs': [],
                             'expr': (
                                 'std::fts::with_options(.name, '