Looks better! A couple of other minor comments, since I'm looking at it:

1. You don't need to assign the last char of the pattern inside the search loop every time around the loop. It will never change (line 1143). Just do it once before the search loop starts.

2. tc_last is the text aligned with the end of the pattern window (line 1142). You don't need to get it again when getting the shift (lines 1201, 1208). bad char is the last char which you already have.