From 9c66f0b2b48dc8ed526b4a253719aa974f71254d Mon Sep 17 00:00:00 2001
From: Lonami Exo <totufals@hotmail.com>
Date: Sun, 24 Dec 2017 15:14:54 +0100
Subject: [PATCH] Fix empty strings not working as expected for flag parameters

---
 telethon_generator/tl_generator.py | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/telethon_generator/tl_generator.py b/telethon_generator/tl_generator.py
index 60f07bd6..f8a9e873 100644
--- a/telethon_generator/tl_generator.py
+++ b/telethon_generator/tl_generator.py
@@ -464,9 +464,11 @@ class TLGenerator:
                 # Vector flags are special since they consist of 3 values,
                 # so we need an extra join here. Note that empty vector flags
                 # should NOT be sent either!
-                builder.write("b'' if not {} else b''.join((".format(name))
+                builder.write("b'' if {0} is None or {0} is False "
+                              "else b''.join((".format(name))
             else:
-                builder.write("b'' if not {} else (".format(name))
+                builder.write("b'' if {0} is None or {0} is False "
+                              "else (".format(name))
 
         if arg.is_vector:
             if arg.use_vector_id:
@@ -495,11 +497,14 @@ class TLGenerator:
                 # There's a flag indicator, but no flag arguments so it's 0
                 builder.write(r"b'\0\0\0\0'")
             else:
-                builder.write("struct.pack('<I', {})".format(
-                    ' | '.join('({} if {} else 0)'.format(
-                        1 << flag.flag_index, 'self.{}'.format(flag.name)
-                    ) for flag in args if flag.is_flag)
-                ))
+                builder.write("struct.pack('<I', ")
+                builder.write(
+                    ' | '.join('(0 if {0} is None or {0} is False else {1})'
+                               .format('self.{}'.format(flag.name),
+                                       1 << flag.flag_index)
+                               for flag in args if flag.is_flag)
+                )
+                builder.write(')')
 
         elif 'int' == arg.type:
             # struct.pack is around 4 times faster than int.to_bytes