autfilt --acceptance-is=Fin-less should reject "f"

* bin/autfilt.cc: Fix detection of Fin-less acceptance.
* tests/core/remfin.test: Add some tests.
* NEWS: Mention the bug.

NEWS

@@ -9,6 +9,9 @@ New in spot 2.5.1.dev (not yet released)
   - remove_fin(), streett_to_generalized_buchi() should never
     return automata with "f" acceptance.
 
+  - "autfilt --acceptance-is=Fin-less" no longer accept automata
+    with "f" acceptance.
+
 New in spot 2.5.1 (2018-02-20)
 
   Library:

bin/autfilt.cc

@@ -1191,7 +1191,7 @@ namespace
             }
         }
       case ACC_FinLess:
-        return !acc.uses_fin_acceptance();
+        return !acc.uses_fin_acceptance() && !acc.is_f();
       }
     SPOT_UNREACHABLE();
   }

tests/core/remfin.test

@@ -1541,3 +1541,10 @@ SPOT_STREETT_CONV_MIN=0 \
 autcross --language-preserved -Ftest1 \
   'SPOT_STREETT_CONV_MIN=1 autfilt --remove-fin %H>%O' \
   'SPOT_STREETT_CONV_MIN=1 autfilt --tgba %H>%O'
+
+ltl2tgba true > h1
+autfilt -F h1 --acceptance-is=Fin-less
+autfilt --complement -F h1 > h2
+autfilt -F h2 --acceptance-is=f
+autfilt -F h2 --acceptance-is=Fin-less && exit 1
+autfilt --remove-fin -F h2 | autfilt --acceptance-is=Fin-less