Patch Turso hash-join planner for correlated subqueries

The join planner picks hash-join for tables inside a correlated subquery
(current query block has non-empty outer_query_refs). The hash build
runs once before outer-column refs are bound, so equality predicates
against outer columns evaluate against NULL and produce 0 rows in the
hash table. Every probe then misses, the scalar subquery returns NULL,
and an outer WHERE filter on the alias discards everything.

Repro: testInformationSchemaTablesFilterByAutoIncrement — the
cols x sqlite_sequence join inside the AUTO_INCREMENT correlated
subquery.

Refuse hash-join when the current query block is itself correlated.
Falls back to nested-loop, which re-evaluates per outer row.

Worth reporting upstream — independent of mysql-on-sqlite.

Author: JanJakes

.github/workflows/phpunit-tests-turso.yml

@@ -638,6 +638,44 @@ jobs:
           print('patched translate_drop_table to use correct database schema for sqlite_sequence')
           PY_FIX_TEMP_DROP_SEQ
 
+          # 18. The join planner picks hash-join for tables inside a correlated
+          #     subquery (current block has non-empty outer_query_refs).
+          #     Hash-build runs once before outer column refs are bound, so
+          #     equality predicates against outer columns evaluate against
+          #     NULL, producing 0 rows in the hash table. Every probe then
+          #     misses, the scalar subquery returns NULL, and an outer
+          #     `WHERE alias > N` filter discards everything.
+          #     Repro: testInformationSchemaTablesFilterByAutoIncrement —
+          #     the cols × sqlite_sequence join inside the AUTO_INCREMENT
+          #     correlated subquery.
+          #     Fix: refuse hash-join when the current query block is
+          #     itself correlated (has outer_query_refs). Falls back to
+          #     nested-loop, which re-evaluates per outer row.
+          python3 - <<'PY_FIX_HASH_JOIN_CORRELATED'
+          p = 'core/translate/optimizer/join.rs'
+          s = open(p).read()
+          old = (
+              "            let allow_hash_join = !rhs_has_selective_seek\n"
+              "                && !probe_table_is_prior_build\n"
+              "                && (!build_has_prior_constraints || build_has_rowid)\n"
+              "                && !chaining_across_outer;\n"
+          )
+          new = (
+              "            // Refuse hash-join when the current query block is itself a\n"
+              "            // correlated subquery (has outer_query_refs). The hash build\n"
+              "            // would materialize once with outer column refs unbound,\n"
+              "            // yielding 0 rows for any predicate against an outer column.\n"
+              "            let allow_hash_join = !rhs_has_selective_seek\n"
+              "                && !probe_table_is_prior_build\n"
+              "                && (!build_has_prior_constraints || build_has_rowid)\n"
+              "                && !chaining_across_outer\n"
+              "                && table_references.outer_query_refs().is_empty();\n"
+          )
+          assert old in s, 'hash-join allow_hash_join block not found'
+          open(p, 'w').write(s.replace(old, new, 1))
+          print('patched join.rs to refuse hash-join in correlated query blocks')
+          PY_FIX_HASH_JOIN_CORRELATED
+
           echo '--- Patched stub! macro ---'
           sed -n '/macro_rules! stub/,/^}$/p' sqlite3/src/lib.rs