Fixed bug in guess mode

Author: dhondta

src/codext/__common__.py

@@ -1370,17 +1370,22 @@ def __make_encodings_dict(include, exclude):
     """ Process encodings inclusion and exclusion lists, listing categories and developping codecs' lists of possible
          encoding names. It also creates a cache with the CodecInfo objects for improving performance. """
     def _develop(d, keep=True):
-        d = d or {}
+        d, names = d or {}, None
         for k, v in d.items():
             l, cc, sc = [], [e for e in v if e in CODECS_CATEGORIES], [e for e in v if e not in CODECS_CATEGORIES]
+            cn = list_encodings(*cc) if (len(cc) > 0 or keep) and len(sc) == 0 else []
+            if len(sc) > 0 and names is None:
+                names = set(list_encodings())
             # list from in-scope categories and then everything that is not a category
-            for enc in ((list_encodings(*cc) if (len(cc) > 0 or keep) and len(sc) == 0 else []) + sc):
+            for enc in cn + sc:
                 g = []
                 for e in (search(enc, False) or [enc]):
                     g.extend(__guess_list(e))
-                if enc in g:  # e.g. "rot-1" => ["rot-1", "rot-2", ...] ; only "rot-1" is to be selected
-                    l.append(enc)
-                else:         # e.g. "rot"   => ["rot-1", "rot-2", ...] ; all the "rot-N" shall be selected
+                # an encoding name selects only itself, while a codec name selects all its encodings, even when it is
+                #  one of them (e.g. "base45" => ["base45", "base45-inv"])
+                if enc in g and enc not in cn and enc not in names:
+                    l.append(enc)  # e.g. "rot-1" => ["rot-1", "rot-2", ...] ; only "rot-1" is to be selected
+                else:              # e.g. "rot"   => ["rot-1", "rot-2", ...] ; all the "rot-N" shall be selected
                     l.extend(g)
             d[k] = list(set(l))
         return d

tests/test_common.py

@@ -184,6 +184,22 @@ def test_guess_decode(self):
         self.assertEqual(txt, _l(codext.guess(b64, "0123456789", max_depth=1, scoring_heuristic=True, include="base")))
         self.assertRaises(ValueError, codext.stopfunc._reload_lang, "DOES_NOT_EXIST")
 
+    def test_guess_codec_variants(self):
+        STR = "This is a test"
+        _g = lambda enc, **kw: codext.guess(codext.encode(STR, enc), "a test", max_depth=1, **kw)
+        # a codec name, given directly or through its category, selects all its encodings to be guessed, even when it is
+        #  one of them (e.g. "base45" => ["base45", "base45-inv"])
+        for enc, inc in [("base45-inv", "base"), ("base45-inv", "base45"), ("whitespace-inv", "stegano"),
+                         ("whitespace-inv", "whitespace")]:
+            self.assertIn((enc, ), _g(enc, include=inc))
+        # both Ook! decoders accept both forms, hence either can be found first
+        for inc in ["esoteric", "ook"]:
+            self.assertIn(STR, _g("ook-short", include=inc).values())
+        # while an encoding name only selects itself
+        self.assertEqual(list(_g("base45-inv", include="base45-inv")), [("base45-inv", )])
+        self.assertEqual(len(_g("base45-inv", include="base45", exclude="base45-inv")), 0)
+        self.assertEqual(len(_g("base45-inv", include="base", exclude="base45")), 0)
+    
     def test_rank_input(self):
         codext.remove("test_codec")
         self.assertRaises(LookupError, codext.encode, "TEST", "test")