Fixed BUG #6747: innodb_locks_unsafe_for_binlog still uses next-key locking.

innobase/row/row0sel.c:
  Fixed bug: innodb_locks_unsafe_for_binlog still uses next-key locking (BUG #6747).
  We do not take gap type locks when using InnoDB startup option 
  innodb_locks_unsafe_for_binlog. Some code polishing also done.

innobase/row/row0sel.c

@@ -642,16 +642,17 @@ row_sel_get_clust_rec(
 		we lock only the record, i.e. next-key locking is
 		not used.
 		*/
-	  if ( srv_locks_unsafe_for_binlog )
-	    {
-		err = lock_clust_rec_read_check_and_lock(0, clust_rec, 
-                        index,node->row_lock_mode, LOCK_REC_NOT_GAP, thr);
-	    }
-	  else
-	    {		
-		err = lock_clust_rec_read_check_and_lock(0, clust_rec, index,
-				node->row_lock_mode, LOCK_ORDINARY, thr);
 
+		if (srv_locks_unsafe_for_binlog) {
+			err = lock_clust_rec_read_check_and_lock(0, 
+					clust_rec, 
+					index, node->row_lock_mode, 
+					LOCK_REC_NOT_GAP, thr);
+		} else {
+			err = lock_clust_rec_read_check_and_lock(0, 
+					clust_rec, 
+					index, node->row_lock_mode, 
+					LOCK_ORDINARY, thr);
 		}
 
 		if (err != DB_SUCCESS) {
@@ -1210,16 +1211,18 @@ rec_loop:
 			not used.
 			*/
 
-                  if ( srv_locks_unsafe_for_binlog )
-		    {
-			err = sel_set_rec_lock(page_rec_get_next(rec), index,
-				node->row_lock_mode, LOCK_REC_NOT_GAP, thr);
-		    } 
-                    else
-		    {
-			err = sel_set_rec_lock(page_rec_get_next(rec), index,
-				node->row_lock_mode, LOCK_ORDINARY, thr);
+			if (srv_locks_unsafe_for_binlog) {
+				err = sel_set_rec_lock(page_rec_get_next(rec), 
+							index,
+							node->row_lock_mode,
+							LOCK_REC_NOT_GAP, thr);
+			} else {
+				err = sel_set_rec_lock(page_rec_get_next(rec), 
+							index,
+							node->row_lock_mode, 
+							LOCK_ORDINARY, thr);
 			}
+
 			if (err != DB_SUCCESS) {
 				/* Note that in this case we will store in pcur
 				the PREDECESSOR of the record we are waiting
@@ -1250,13 +1253,10 @@ rec_loop:
 		not used.
 		*/
 
-                  if ( srv_locks_unsafe_for_binlog )
-		    {
+		if (srv_locks_unsafe_for_binlog) {
 			err = sel_set_rec_lock(rec, index, node->row_lock_mode,
 						LOCK_REC_NOT_GAP, thr);
-		    } 
-		  else
-		    {
+		} else {
 			err = sel_set_rec_lock(rec, index, node->row_lock_mode,
 						LOCK_ORDINARY, thr);
 		}
@@ -3209,8 +3209,7 @@ rec_loop:
 			we do not lock gaps. Supremum record is really
 			a gap and therefore we do not set locks there. */
 			
-			if ( srv_locks_unsafe_for_binlog == FALSE )
-			{
+			if (srv_locks_unsafe_for_binlog == FALSE) {
 				err = sel_set_rec_lock(rec, index,
 						prebuilt->select_lock_type,
 						LOCK_ORDINARY, thr);
@@ -3312,11 +3311,18 @@ rec_loop:
 
 			if (prebuilt->select_lock_type != LOCK_NONE
 		    	    && set_also_gap_locks) {
-				/* Try to place a lock on the index record */
+
+				/* Try to place a gap lock on the index 
+				record only if innodb_locks_unsafe_for_binlog
+				option is not set */
+
+				if (srv_locks_unsafe_for_binlog == FALSE) { 
 
 					err = sel_set_rec_lock(rec, index,
 						prebuilt->select_lock_type,
 						LOCK_GAP, thr);
+				}
+
 				if (err != DB_SUCCESS) {
 
 					goto lock_wait_or_error;
@@ -3338,11 +3344,18 @@ rec_loop:
 			
 			if (prebuilt->select_lock_type != LOCK_NONE
 			    && set_also_gap_locks) {
-				/* Try to place a lock on the index record */	
+
+				/* Try to place a gap lock on the index 
+				record only if innodb_locks_unsafe_for_binlog
+				option is not set */
+
+				if (srv_locks_unsafe_for_binlog == FALSE) {
 
 					err = sel_set_rec_lock(rec, index,
 						prebuilt->select_lock_type,
 						LOCK_GAP, thr);
+				}
+
 				if (err != DB_SUCCESS) {
 
 					goto lock_wait_or_error;
@@ -3378,16 +3391,13 @@ rec_loop:
 		} else {
 			/* If innodb_locks_unsafe_for_binlog option is used, 
 			we lock only the record, i.e. next-key locking is
-                           not used.
-	                */
-	                if ( srv_locks_unsafe_for_binlog )
-	                {
+			not used. */
+
+			if (srv_locks_unsafe_for_binlog) {
 				err = sel_set_rec_lock(rec, index,
 						prebuilt->select_lock_type,
 						LOCK_REC_NOT_GAP, thr);
-			}
-			else
-			{
+			} else {
 				err = sel_set_rec_lock(rec, index,
 						prebuilt->select_lock_type,
 						LOCK_ORDINARY, thr);