MDEV-9148: Assertion `thd->stmt_arena != thd->progress.arena' failed in thd_progress_init

Called thd_progress_init() from several threads used for FT-index
creation. For FT-indexes, need better way to report progress,
remove current one for them.

storage/innobase/row/row0merge.cc

@@ -2327,7 +2327,10 @@ row_merge_sort(
 	of file marker).  Thus, it must be at least one block. */
 	ut_ad(file->offset > 0);
 
+	/* Progress report only for "normal" indexes. */
+	if (!(dup->index->type & DICT_FTS)) {
 		thd_progress_init(trx->mysql_thd, 1);
+	}
 
 	/* Merge the runs until we have one big run */
 	do {
@@ -2335,8 +2338,11 @@ row_merge_sort(
 				  &num_runs, run_offset);
 
 		/* Report progress of merge sort to MySQL for
-		show processlist progress field */
+		show processlist progress field only for
+		"normal" indexes. */
+		if (!(dup->index->type & DICT_FTS)) {
 			thd_progress_report(trx->mysql_thd, file->offset - num_runs, file->offset);
+		}
 
 		if (error != DB_SUCCESS) {
 			break;
@@ -2347,7 +2353,9 @@ row_merge_sort(
 
 	mem_free(run_offset);
 
+	if (!(dup->index->type & DICT_FTS)) {
 		thd_progress_end(trx->mysql_thd);
+	}
 
 	DBUG_RETURN(error);
 }

storage/xtradb/row/row0merge.cc

@@ -2335,7 +2335,10 @@ row_merge_sort(
 	of file marker).  Thus, it must be at least one block. */
 	ut_ad(file->offset > 0);
 
+	/* Progress report only for "normal" indexes. */
+	if (!(dup->index->type & DICT_FTS)) {
 		thd_progress_init(trx->mysql_thd, 1);
+	}
 
 	/* Merge the runs until we have one big run */
 	do {
@@ -2343,9 +2346,13 @@ row_merge_sort(
 				  &num_runs, run_offset);
 
 		/* Report progress of merge sort to MySQL for
-		show processlist progress field */
+		show processlist progress field only for
+		"normal" indexes. */
+		if (!(dup->index->type & DICT_FTS)) {
 			thd_progress_report(trx->mysql_thd, file->offset - num_runs, file->offset);
 
+		}
+
 		if (error != DB_SUCCESS) {
 			break;
 		}
@@ -2355,7 +2362,9 @@ row_merge_sort(
 
 	mem_free(run_offset);
 
+	if (!(dup->index->type & DICT_FTS)) {
 		thd_progress_end(trx->mysql_thd);
+	}
 
 	DBUG_RETURN(error);
 }