Check the length of the screencap before indexing into it

Author: JeffLIrion

ppadb/command/transport_async/__init__.py

@@ -34,7 +34,7 @@ async def screencap(self):
             await conn.send(cmd)
             result = await conn.read_all()
 
-        if result[5] == 0x0d:
+        if result and len(result) > 5 and result[5] == 0x0d:
             return result.replace(b'\r\n', b'\n')
         else:
             return result