fix to optimization to deal with identical nit sot of different lengths

theano/scan_module/scan_opt.py

@@ -1385,10 +1385,46 @@ def scan_merge_inouts(node):
         seen.append((i, o))
         return o
 
+    def map_nitsot_out(i, o, sh, seen):
+        for p,(si, so, ssh) in enumerate(seen):
+            if equal_computations([i], [si], left, right):
+                if equal_computations([sh], [ssh]):
+                    return so
+                try:
+                    vsh = int(opt.get_constant_value(sh))
+                    vssh = int(opt.get_constant_value(ssh))
+                except:
+                    return o
+                if vsh == vssh:
+                    return so
+                elif vsh > vssh:
+                    seen[p] = (i,o,sh)
+                    return o
+                else:
+                    return so[:vsh]
+        seen.append((i, o, sh))
+        return o
+
     seen = []
-    na.outer_out_nit_sot = [map_out(i, o, seen)
-                            for i, o in zip(na.inner_out_nit_sot,
-                                            na.outer_out_nit_sot)]
+
+    shapes = []
+    for x in na.outer_in_nit_sot:
+        if x.ndim > 0:
+            shapes.append(
+                node.fgraph.shape_feature.shape_of[x][0])
+        else:
+            shapes.append(x)
+    tmp = [map_nitsot_out(i, o, sh, seen)
+                            for i, o, sh in zip(na.inner_out_nit_sot,
+                                            na.outer_out_nit_sot,
+                                            shapes)]
+    na.outer_out_nit_sot = [map_nitsot_out(i, o, sh, seen)
+                            for i, o, sh in zip(na.inner_out_nit_sot,
+                                            na.outer_out_nit_sot,
+                                            shapes)]
+
+
+
 
     seen = []
     na.outer_out_sit_sot = [map_out(i, o, seen)