delete check return value from _getVisibleCell function

cell/view/WorksheetView.js

@@ -6917,11 +6917,6 @@
 		var c1 = mc ? mc.c1 : cell.col;
 		var r1 = mc ? mc.r1 : cell.row;
 		var c = this._getVisibleCell(c1, r1);
-
-		if (c === undefined) {
-			asc_debug("log", "Unknown cell's info: col = " + c1 + ", row = " + r1);
-			return {};
-		}
 		var font = c.getFont();
 		var fa = font.getVerticalAlign();
 		var fc = font.getColor();
@@ -8674,14 +8669,12 @@
                         c = mc ? mc.c1 : activeCell.col;
                         r = mc ? mc.r1 : activeCell.row;
                         cell = t._getVisibleCell(c, r);
-                        if (undefined !== cell) {
 						var oldFontSize = cell.getFont().getSize();
 						var newFontSize = asc_incDecFonSize(val, oldFontSize);
 						if (null !== newFontSize) {
 							range.setFontsize(newFontSize);
 							canChangeColWidth = c_oAscCanChangeColWidth.numbers;
 						}
-                        }
                         break;
                     case "style":
                         range.setCellStyle(val);
@@ -10603,10 +10596,6 @@
                   ++options.countReplace;
 
                   var c = t._getVisibleCell(cell.c1, cell.r1);
-
-                  if (c === undefined) {
-                      asc_debug("log", "Unknown cell's info: col = " + cell.c1 + ", row = " + cell.r1);
-                  } else {
 				  var cellValue = c.getValueForEdit();
 				  cellValue = cellValue.replace(valueForSearching, options.replaceWith);
 
@@ -10621,7 +10610,6 @@
 				  t._saveCellValueAfterEdit(oCellEdit, c, newValue, /*flags*/undefined, /*skipNLCheck*/false,
                       /*isNotHistory*/true, /*lockDraw*/true);
               }
-              }
 
               window.setTimeout(function () {
                   t._replaceCellText(aReplaceCells, valueForSearching, options, lockDraw, callback, oneUser);
@@ -11036,11 +11024,6 @@
         var activeCell = selectionRange.activeCell;
         var c = t._getVisibleCell(activeCell.col, activeCell.row);
         var v, copyValue;
-
-        if (!c) {
-            throw "Can not get cell data (col=" + activeCell.col + ", row=" + activeCell.row + ")";
-        }
-
         // get first fragment and change its text
         v = c.getValueForEdit2().slice(0, 1);
         // Создаем новый массив, т.к. getValueForEdit2 возвращает ссылку