Fixed two DFW bugs

1. Unregistered FB2 bug - expression index dependencies was tracked not correctly.
2. SF #1250150

src/jrd/dfw.epp

@@ -167,9 +167,6 @@ static bool add_difference(thread_db*, SSHORT, DeferredWork*, jrd_tra*);
 static bool delete_difference(thread_db*, SSHORT, DeferredWork*, jrd_tra*);
 static bool begin_backup(thread_db*, SSHORT, DeferredWork*, jrd_tra*);
 static bool end_backup(thread_db*, SSHORT, DeferredWork*, jrd_tra*);
-static Lock* protect_relation(thread_db*, jrd_tra*, jrd_rel*, bool&);
-static void release_protect_lock(thread_db*, jrd_tra*, Lock*);
-static void check_partners(thread_db*, const USHORT);
 
 /* ---------------------------------------------------------------- */
 
@@ -193,6 +190,10 @@ static void	setup_trigger_details(thread_db*, jrd_rel*, blb*, trig_vec**, const
 	const TEXT*, bool);
 static bool validate_text_type (thread_db*, const TemporaryField*);
 
+static Lock* protect_relation(thread_db*, jrd_tra*, jrd_rel*, bool&);
+static void release_protect_lock(thread_db*, jrd_tra*, Lock*);
+static void check_partners(thread_db*, const USHORT);
+
 static const UCHAR nonnull_validation_blr[] =
 {
 	blr_version5,
@@ -213,6 +214,7 @@ static const deferred_task task_table[] =
 	{ dfw_add_file, add_file },
 	{ dfw_add_shadow, add_shadow },
 	{ dfw_delete_index, delete_index },
+	{ dfw_delete_expression_index, delete_index },
 	{ dfw_delete_rfr, delete_rfr },
 	{ dfw_delete_relation, delete_relation },
 	{ dfw_delete_shadow, delete_shadow },
@@ -226,7 +228,6 @@ static const deferred_task task_table[] =
 #ifdef EXPRESSION_INDICES
 	{ dfw_create_expression_index, PCMET_expression_index },
 #endif
-	{ dfw_delete_expression_index, delete_index },
 	{ dfw_grant, GRANT_privileges },
 	{ dfw_create_trigger, create_trigger },
 	{ dfw_delete_trigger, delete_trigger },
@@ -637,7 +638,7 @@ DeferredWork* DFW_post_work(jrd_tra* transaction, enum dfw_t type, const dsc* de
 }
 
 
-void DFW_post_work_arg( jrd_tra* transaction, DeferredWork* work, const dsc* desc,
+DeferredWork* DFW_post_work_arg( jrd_tra* transaction, DeferredWork* work, const dsc* desc,
 	USHORT id)
 {
 /**************************************
@@ -651,7 +652,7 @@ void DFW_post_work_arg( jrd_tra* transaction, DeferredWork* work, const dsc* des
  *
  **************************************/
 
-	post_work(transaction,
+	return post_work(transaction,
 			  work->dfw_sav_number,
 			  &work->dfw_args,
 			  work->dfw_type,
@@ -2443,18 +2444,36 @@ static bool delete_index(thread_db* tdbb, SSHORT phase, DeferredWork* work,
 		IDX_delete_index(tdbb, relation, id);
 		if (work->dfw_type == dfw_delete_expression_index)
 		{
+			// for expression index there are dependincies  
+			// therefore work->dfw_args was set in VIO_erase
+			// to let us know that expression index name
+			fb_assert(work->dfw_args);
+
+			const DeferredWork* arg = work->dfw_args;
+			while(arg && (arg->dfw_type != dfw_arg_index_name)) 
+			{
+				arg = arg->dfw_next;
+			}
+
+			fb_assert(arg);
 			MET_delete_dependencies(tdbb,
-									work->dfw_name,
+				arg->dfw_name, 
 									obj_expression_index);
 		}
 
 		// if index was bound to deleted FK constraint 
 		// then work->dfw_args was set in VIO_erase
-		if (work->dfw_args) {
+		const DeferredWork* arg = work->dfw_args;
-			if (work->dfw_args->dfw_id) {
+		while(arg && (arg->dfw_type != dfw_arg_partner_rel_id)) 
+		{
+			arg = arg->dfw_next;
+		}
+
+		if (arg) {
+			if (arg->dfw_id) {
 				check_partners(tdbb, relation->rel_id);
-				if (relation->rel_id != work->dfw_args->dfw_id) {
+				if (relation->rel_id != arg->dfw_id) {
-					check_partners(tdbb, work->dfw_args->dfw_id);
+					check_partners(tdbb, arg->dfw_id);
 				}
 			}
 			else {
@@ -3136,7 +3155,7 @@ static bool find_depend_in_dfw(	thread_db*	tdbb,
 		dfw_type = dfw_delete_procedure;
 		break;
 	case obj_expression_index:
-		dfw_type = dfw_delete_index;
+		dfw_type = dfw_delete_expression_index;
 		break;
 	default:
 		fb_assert(false);
@@ -3154,6 +3173,21 @@ static bool find_depend_in_dfw(	thread_db*	tdbb,
 		{
 			return true;
 		}
+
+		if (work->dfw_type == dfw_type && 
+			dfw_type == dfw_delete_expression_index)
+		{
+			const DeferredWork* arg = work->dfw_args;
+			while (arg)
+			{
+				if (arg->dfw_type == dfw_arg_index_name &&
+					arg->dfw_name == object_name)
+				{
+					return true;
+				}
+				arg = arg->dfw_next;
+			}
+		}
 	}
 
 	if (dfw_type == dfw_delete_global)

src/jrd/dfw_proto.h

@@ -31,7 +31,7 @@ void DFW_perform_system_work(void);
 void DFW_perform_work(Jrd::jrd_tra*);
 void DFW_perform_post_commit_work(Jrd::jrd_tra*);
 Jrd::DeferredWork* DFW_post_work(Jrd::jrd_tra*, enum Jrd::dfw_t, const dsc*, USHORT);
-void DFW_post_work_arg(Jrd::jrd_tra*, Jrd::DeferredWork*, const dsc*, USHORT);
+Jrd::DeferredWork* DFW_post_work_arg(Jrd::jrd_tra*, Jrd::DeferredWork*, const dsc*, USHORT);
 void DFW_update_index(const TEXT*, USHORT, const Jrd::SelectivityList&);
 
 #endif // JRD_DFW_PROTO_H

src/jrd/tra.h

@@ -244,7 +244,12 @@ enum dfw_t {
 	dfw_add_difference,
 	dfw_delete_difference,
 	dfw_begin_backup,
-	dfw_end_backup
+	dfw_end_backup,
+
+	// deffered works argument types
+	dfw_arg_index_name,		// index name for dfw_delete_expression_index, mandatory
+	dfw_arg_partner_rel_id,	// partner relation id for dfw_delete_index if index is FK, optional
+	dfw_arg_proc_name		// procedure name for dfw_delete_prm, mandatory
 };
 
 class DeferredWork : public pool_alloc<type_dfw>

src/jrd/vio.cpp

@@ -1327,6 +1327,12 @@ void VIO_erase(thread_db* tdbb, record_param* rpb, jrd_tra* transaction)
 				{
 					work = DFW_post_work(transaction, dfw_delete_expression_index,
 								  &desc, id);
+
+					// add expression index name to correctly delete dependencies
+					DSC idx_name;
+					EVL_field(0, rpb->rpb_record, f_idx_name, &idx_name);
+					DeferredWork* arg = DFW_post_work_arg(transaction, work, &idx_name, id);
+					arg->dfw_type = dfw_arg_index_name;
 				}
 				else
 				{
@@ -1353,12 +1359,14 @@ void VIO_erase(thread_db* tdbb, record_param* rpb, jrd_tra* transaction)
 					(MET_lookup_partner(tdbb, r2, &idx, idx_name)) &&
 					(partner = MET_lookup_relation_id(tdbb, idx.idx_primary_relation, false)) )
 				{
-					DFW_post_work_arg(transaction, work, 0, partner->rel_id);
+					DeferredWork* arg = DFW_post_work_arg(transaction, work, 0, partner->rel_id);
+					arg->dfw_type = dfw_arg_partner_rel_id;
 				}
 				else {	// can't find partner relation - impossible ?
 					// add empty argument to let DFW know dropping
 					// index was bound with FK
-					DFW_post_work_arg(transaction, work, 0, 0);
+					DeferredWork* arg = DFW_post_work_arg(transaction, work, 0, 0);
+					arg->dfw_type = dfw_arg_partner_rel_id;
 				}
 			}
 			break;
@@ -1385,8 +1393,13 @@ void VIO_erase(thread_db* tdbb, record_param* rpb, jrd_tra* transaction)
 			MOV_get_metadata_str(&desc, procedure_name, sizeof(procedure_name));
 			if ( (procedure = MET_lookup_procedure(tdbb, procedure_name, true)) )
 			{
-				DFW_post_work(transaction, dfw_delete_prm, &desc2,
+				work = DFW_post_work(transaction, dfw_delete_prm, &desc2,
 							  procedure->prc_id);
+
+				// procedure name to track parameter dependencies
+				DeferredWork* arg = DFW_post_work_arg(transaction, work, &desc, 
+										procedure->prc_id);
+				arg->dfw_type = dfw_arg_proc_name;
 			}
 			EVL_field(0, rpb->rpb_record, f_prm_sname, &desc2);
 			DFW_post_work(transaction, dfw_delete_global, &desc2, 0);
@@ -3826,13 +3839,13 @@ static THREAD_ENTRY_DECLARE garbage_collector(THREAD_ENTRY_PARAM arg)
 			   Express interest in the relation to prevent it from being deleted
 			   out from under us while garbage collection is in-progress. */
 
-			//hvlad: skip system relations
 			vec* vector = dbb->dbb_relations;
 			for (ULONG id = 0; vector && id < vector->count(); ++id) {
 				relation = (jrd_rel*) (*vector)[id];
 				RelationGarbage *relGarbage = 
 					relation ? (RelationGarbage*)relation->rel_garbage : NULL;
 
+				//hvlad: skip system relations
 				if (relation && (relation->rel_gc_bitmap || relGarbage) &&
 					!(relation->rel_flags & (REL_deleted | REL_deleting | REL_system)))
 				{