Fix to a bug in scan sequences taps

The bug was reported by Nicolas, and it happens when you have a single tap for a sequence that is different from 0.

Fix to a bug in scan sequences taps
647b2c89 · Razvan Pascanu · b8165faa · 647b2c89
--- a/theano/scan_module/scan.py
+++ b/theano/scan_module/scan.py
@@ -492,7 +492,10 @@ def scan(fn,
                else:
                    offset = 0
                if maxtap == mintap and maxtap != 0:
-                    nw_seq = seq['input'][:abs(maxtap)]
+                    if maxtap < 0:
+                        nw_seq = seq['input'][:maxtap]
+                    else:
+                        nw_seq = seq['input'][maxtap:]
                elif maxtap - k != 0:
                    nw_seq = seq['input'][offset + k - mintap: -(maxtap - k)]
                else: