updated for version 7.4.186
Problem:    Insert in Visual mode sometimes gives incorrect results.
            (Dominique Pelle)
Solution:   Remember the original insert start position. (Christian Brabandt,
            Dominique Pelle)
diff --git a/src/ops.c b/src/ops.c
index 8505f64..4517e42 100644
--- a/src/ops.c
+++ b/src/ops.c
@@ -2643,20 +2643,20 @@
 
 	/* The user may have moved the cursor before inserting something, try
 	 * to adjust the block for that. */
-	if (oap->start.lnum == curbuf->b_op_start.lnum && !bd.is_MAX)
+	if (oap->start.lnum == curbuf->b_op_start_orig.lnum && !bd.is_MAX)
 	{
 	    if (oap->op_type == OP_INSERT
-		    && oap->start.col != curbuf->b_op_start.col)
+		    && oap->start.col != curbuf->b_op_start_orig.col)
 	    {
-		oap->start.col = curbuf->b_op_start.col;
+		oap->start.col = curbuf->b_op_start_orig.col;
 		pre_textlen -= getviscol2(oap->start.col, oap->start.coladd)
 							    - oap->start_vcol;
 		oap->start_vcol = getviscol2(oap->start.col, oap->start.coladd);
 	    }
 	    else if (oap->op_type == OP_APPEND
-		    && oap->end.col >= curbuf->b_op_start.col)
+		    && oap->end.col >= curbuf->b_op_start_orig.col)
 	    {
-		oap->start.col = curbuf->b_op_start.col;
+		oap->start.col = curbuf->b_op_start_orig.col;
 		/* reset pre_textlen to the value of OP_INSERT */
 		pre_textlen += bd.textlen;
 		pre_textlen -= getviscol2(oap->start.col, oap->start.coladd)