Avoid crash when using inset-select-all in tabular

When changing cell idx, it is important to set the pit to a reasonable
value.

(cherry picked from commit a69e01d0b4)

src/BufferView.cpp

@@ -1889,10 +1889,12 @@ void BufferView::dispatch(FuncRequest const & cmd, DispatchResult & dr)
 			// At least one complete cell is selected and inset is a table.
 			// Select all cells
 			cur.idx() = 0;
+			cur.pit() = 0;
 			cur.pos() = 0;
 			cur.resetAnchor();
 			cur.selection(true);
 			cur.idx() = cur.lastidx();
+			cur.pit() = cur.lastpit();
 			cur.pos() = cur.lastpos();
 		} else {
 			// select current cell

status.23x

@@ -117,6 +117,8 @@ What's new
 
 - Fix cases where text is offset vertically (bug 10532, 10767).
 
+- Fix crash when using inset-select-all in tabular.
+
 
 * INTERNALS