Options: Fix block encoding

Closes: #130
chrysn · Nov 17, 2018 · 9bd612d · 9bd612d
1 parent 21f7135
commit 9bd612d
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Showing 2 changed files with 6 additions and 2 deletions.
diff --git a/aiocoap/options.py b/aiocoap/options.py
@@ -162,7 +162,9 @@ def encode(self):
             data.append(bytes([((delta & 0x0F) << 4) + (length & 0x0F)]))
             data.append(extended_delta)
             data.append(extended_length)
-            data.append(option.encode())
+            optiondata = option.encode()
+            assert len(optiondata) == option.length, "Option announced different data length than produced"
+            data.append(optiondata)
             current_opt_num = option.number
         return (b''.join(data))
 

diff --git a/aiocoap/optiontypes.py b/aiocoap/optiontypes.py
@@ -196,7 +196,9 @@ def decode(self, rawdata):
         self.value = self.BlockwiseTuple(block_number=(as_integer >> 4), more=bool(as_integer & 0x08), size_exponent=(as_integer & 0x07))
 
     def _length(self):
-        return ((self.value[0].bit_length() + 3) // 8 + 1)
+        if self.value.block_number == 0:
+            return int(self.value.more or (self.value.size_exponent != 0))
+        return ((self.value.block_number.bit_length() + 3) // 8 + 1)
     length = property(_length)
 
     def __str__(self):