validate put parameters

We should at least check against common usage errors

discid/disc.py

@@ -146,12 +146,16 @@ def read(self, device=None, features=[]):
 
     _LIB.discid_put.argtypes = (c_void_p, c_int, c_int, c_void_p)
     _LIB.discid_put.restype = c_int
-    # TODO: test if input is valid (int rather than string, ...)
     def put(self, first, last, disc_sectors, track_offsets):
         """Creates a TOC based on the input given.
 
         The user is supposed to use :func:`discid.put`.
         """
+        # check for common usage errors
+        if (len(track_offsets) != last - first + 1
+                or False in [disc_sectors >= off for off in track_offsets]):
+            raise DiscError("invalid parameters given")
+
         # only the "read" (= TOC) feature is supported by put
         self._requested_features = ["read"]
 

test_discid.py

@@ -72,13 +72,13 @@ def test_device_encoding(self):
         self.assertRaises(discid.DiscError, discid.read, devicebytes)
 
     def test_put_fail(self):
-        # it will only fail because first > last
-        first = 15
-        last = 1
-        sectors = 258725
-        offsets = [150, 17510, 33275, 45910] # also wrong
+        # not enough offsets
+        self.assertRaises(discid.DiscError, discid.put, 1, 2, 150, [150])
+        # too many offsets
         self.assertRaises(discid.DiscError,
-                          discid.put, first, last, sectors, offsets)
+                          discid.put, 1, 2, 1000, [150, 500, 750])
+        # total sectors / offset mismatch
+        self.assertRaises(discid.DiscError, discid.put, 1, 2, 150, [150, 500])
 
     def test_put_success(self):
         test_disc = test_discs[0]