diff --git a/storage/innobase/include/row0merge.h b/storage/innobase/include/row0merge.h
index fa00700b225bf..196543f25e194 100644
--- a/storage/innobase/include/row0merge.h
+++ b/storage/innobase/include/row0merge.h
@@ -41,6 +41,9 @@ Created 13/06/2005 Jan Lindstrom
 #include "lock0types.h"
 #include "srv0srv.h"
 
+/* Reserve free space from every block for key_version */
+#define ROW_MERGE_RESERVE_SIZE 4
+
 /* Cluster index read task is mandatory */
 #define COST_READ_CLUSTERED_INDEX            1.0
 
diff --git a/storage/innobase/row/row0ftsort.cc b/storage/innobase/row/row0ftsort.cc
index f970938f72961..4c021973b9a12 100644
--- a/storage/innobase/row/row0ftsort.cc
+++ b/storage/innobase/row/row0ftsort.cc
@@ -557,9 +557,11 @@ row_merge_fts_doc_tokenize(
 		fts_max_token_size, add one extra size and one extra byte */
 		cur_len += 2;
 
-		/* Reserve one byte for the end marker of row_merge_block_t. */
+		/* Reserve one byte for the end marker of row_merge_block_t
+		and we have reserved ROW_MERGE_RESERVE_SIZE (= 4) for
+		encryption key_version in the beginning of the buffer. */
 		if (buf->total_size + data_size[idx] + cur_len
-		    >= srv_sort_buf_size - 1) {
+			>= (srv_sort_buf_size - 1 - ROW_MERGE_RESERVE_SIZE)) {
 
 			buf_full = TRUE;
 			break;
diff --git a/storage/innobase/row/row0merge.cc b/storage/innobase/row/row0merge.cc
index c921c5b7318e6..f5cc33fb57d4a 100644
--- a/storage/innobase/row/row0merge.cc
+++ b/storage/innobase/row/row0merge.cc
@@ -78,8 +78,6 @@ UNIV_INTERN char	srv_disable_sort_file_cache;
 /* Maximum pending doc memory limit in bytes for a fts tokenization thread */
 #define FTS_PENDING_DOC_MEMORY_LIMIT	1000000
 
-/* Reserve free space from every block for key_version */
-#define ROW_MERGE_RESERVE_SIZE 4
 
 /******************************************************//**
 Encrypt a merge block. */
@@ -2571,7 +2569,11 @@ row_merge_sort(
 	of file marker).  Thus, it must be at least one block. */
 	ut_ad(file->offset > 0);
 
-	thd_progress_init(trx->mysql_thd, num_runs);
+	/* Progress report only for "normal" indexes. */
+	if (!(dup->index->type & DICT_FTS)) {
+		thd_progress_init(trx->mysql_thd, num_runs);
+	}
+
 	sql_print_information("InnoDB: Online DDL : merge-sorting has estimated %lu runs", num_runs);
 
 	/* Merge the runs until we have one big run */
@@ -2580,7 +2582,10 @@ row_merge_sort(
 
 		/* Report progress of merge sort to MySQL for
 		show processlist progress field */
-		thd_progress_report(trx->mysql_thd, cur_run, num_runs);
+		/* Progress report only for "normal" indexes. */
+		if (!(dup->index->type & DICT_FTS)) {
+			thd_progress_report(trx->mysql_thd, cur_run, num_runs);
+		}
 		sql_print_information("InnoDB: Online DDL : merge-sorting current run %lu estimated %lu runs", cur_run, num_runs);
 
 		error = row_merge(trx, dup, file, block, tmpfd,
@@ -2605,7 +2610,10 @@ row_merge_sort(
 
 	mem_free(run_offset);
 
-	thd_progress_end(trx->mysql_thd);
+	/* Progress report only for "normal" indexes. */
+	if (!(dup->index->type & DICT_FTS)) {
+		thd_progress_end(trx->mysql_thd);
+	}
 
 	DBUG_RETURN(error);
 }
diff --git a/storage/xtradb/include/row0merge.h b/storage/xtradb/include/row0merge.h
index fa00700b225bf..196543f25e194 100644
--- a/storage/xtradb/include/row0merge.h
+++ b/storage/xtradb/include/row0merge.h
@@ -41,6 +41,9 @@ Created 13/06/2005 Jan Lindstrom
 #include "lock0types.h"
 #include "srv0srv.h"
 
+/* Reserve free space from every block for key_version */
+#define ROW_MERGE_RESERVE_SIZE 4
+
 /* Cluster index read task is mandatory */
 #define COST_READ_CLUSTERED_INDEX            1.0
 
diff --git a/storage/xtradb/row/row0ftsort.cc b/storage/xtradb/row/row0ftsort.cc
index 55ac0a7d42343..c7a5b51ef5541 100644
--- a/storage/xtradb/row/row0ftsort.cc
+++ b/storage/xtradb/row/row0ftsort.cc
@@ -560,9 +560,11 @@ row_merge_fts_doc_tokenize(
 		fts_max_token_size, add one extra size and one extra byte */
 		cur_len += 2;
 
-		/* Reserve one byte for the end marker of row_merge_block_t. */
+		/* Reserve one byte for the end marker of row_merge_block_t
+		and we have reserved ROW_MERGE_RESERVE_SIZE (= 4) for
+		encryption key_version in the beginning of the buffer. */
 		if (buf->total_size + data_size[idx] + cur_len
-		    >= srv_sort_buf_size - 1) {
+			>= (srv_sort_buf_size - 1 - ROW_MERGE_RESERVE_SIZE)) {
 
 			buf_full = TRUE;
 			break;
diff --git a/storage/xtradb/row/row0merge.cc b/storage/xtradb/row/row0merge.cc
index 3ac18eb95d9cc..8e0ed3780ae07 100644
--- a/storage/xtradb/row/row0merge.cc
+++ b/storage/xtradb/row/row0merge.cc
@@ -78,8 +78,6 @@ UNIV_INTERN char	srv_disable_sort_file_cache;
 /* Maximum pending doc memory limit in bytes for a fts tokenization thread */
 #define FTS_PENDING_DOC_MEMORY_LIMIT	1000000
 
-/* Reserve free space from every block for key_version */
-#define ROW_MERGE_RESERVE_SIZE 4
 
 /******************************************************//**
 Encrypt a merge block. */
@@ -2578,7 +2576,11 @@ row_merge_sort(
 	of file marker).  Thus, it must be at least one block. */
 	ut_ad(file->offset > 0);
 
-	thd_progress_init(trx->mysql_thd, num_runs);
+	/* Progress report only for "normal" indexes. */
+	if (!(dup->index->type & DICT_FTS)) {
+		thd_progress_init(trx->mysql_thd, num_runs);
+	}
+
 	sql_print_information("InnoDB: Online DDL : merge-sorting has estimated %lu runs", num_runs);
 
 	/* Merge the runs until we have one big run */
@@ -2587,7 +2589,10 @@ row_merge_sort(
 
 		/* Report progress of merge sort to MySQL for
 		show processlist progress field */
-		thd_progress_report(trx->mysql_thd, cur_run, num_runs);
+		/* Progress report only for "normal" indexes. */
+		if (!(dup->index->type & DICT_FTS)) {
+			thd_progress_report(trx->mysql_thd, cur_run, num_runs);
+		}
 		sql_print_information("InnoDB: Online DDL : merge-sorting current run %lu estimated %lu runs", cur_run, num_runs);
 
 		error = row_merge(trx, dup, file, block, tmpfd,
@@ -2612,7 +2617,10 @@ row_merge_sort(
 
 	mem_free(run_offset);
 
-	thd_progress_end(trx->mysql_thd);
+	/* Progress report only for "normal" indexes. */
+	if (!(dup->index->type & DICT_FTS)) {
+		thd_progress_end(trx->mysql_thd);
+	}
 
 	DBUG_RETURN(error);
 }