Bug 797971 - Inserting description text behaves oddly

This is best observed when trying to insert a character, say x when the
cursor is before the last character, the cursor will jump to the end
like... ABCD|E results in ABCDxE|

It can also affect when inserting/changing text that has come from the
quick fill the cursor may end up in the wrong place.

Changed a test condition to use the incoming new character length value
instead of the existing cell one.

gnucash/register/register-core/quickfillcell.c

@@ -198,7 +198,7 @@ gnc_quickfill_cell_modify_verify (BasicCell *_cell,
     }
 
     /* If we are inserting in the middle, just accept */
-    if (*cursor_position < _cell->value_chars)
+    if (*cursor_position < newval_chars)
     {
         gnc_basic_cell_set_value_internal (&cell->cell, newval);
         gnc_quickfill_cell_set_original (cell, NULL);
@@ -233,8 +233,6 @@ gnc_quickfill_cell_modify_verify (BasicCell *_cell,
         if (cell->original != NULL)
             newval = cell->original;
 
-        *cursor_position = -1;
-
         gnc_basic_cell_set_value_internal (&cell->cell, newval);
         return;
     }