Merge pull request rails#53870 from byroot/stmt-pool-delete-fix

StatementPool#delete don't assume the statement existed

Author: byroot

activerecord/lib/active_record/connection_adapters/statement_pool.rb

@@ -50,8 +50,10 @@ def reset
       end
 
       def delete(key)
-        dealloc cache[key]
-        cache.delete(key)
+        if stmt = cache.delete(key)
+          dealloc(stmt)
+        end
+        stmt
       end
 
       private

activerecord/test/cases/connection_adapters/statement_pool_test.rb

@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+require "cases/helper"
+
+module ActiveRecord
+  module ConnectionAdapters
+    class StatementPoolTest < ActiveRecord::TestCase
+      class TestPool < StatementPool
+        private
+          def dealloc(stmt)
+            raise ArgumentError unless stmt
+          end
+      end
+
+      setup do
+        @pool = TestPool.new
+      end
+
+      test "#delete doesn't call dealloc if the statement didn't exist" do
+        stmt = Object.new
+        sql = "SELECT 1"
+        @pool[sql] = stmt
+        assert_same stmt, @pool[sql]
+        assert_same stmt, @pool.delete(sql)
+        assert_nil @pool.delete(sql)
+      end
+    end
+  end
+end