create_subprocess_exec should treat env={} as empty environment (#439) (#454)

* Empty env dict represents empty environment. * Allow 0-length cstring array Co-authored-by: Fantix King <[email protected]>

Author: byllyfish

tests/test_process.py

@@ -50,6 +50,22 @@ async def test():
 
 self.loop.run_until_complete(test())
 
+deftest_process_env_2(self):
+asyncdeftest():
+cmd='env'
+env={} # empty environment
+proc=awaitasyncio.create_subprocess_exec(
+cmd,
+env=env,
+stdout=subprocess.PIPE,
+stderr=subprocess.PIPE)
+
+out, _=awaitproc.communicate()
+self.assertEqual(out, b'')
+self.assertEqual(proc.returncode, 0)
+
+self.loop.run_until_complete(test())
+
 deftest_process_cwd_1(self):
 asyncdeftest():
 cmd='pwd'

uvloop/handles/process.pyx

@@ -217,9 +217,6 @@ cdef class UVProcess(UVHandle):
 
 char**ret
 
-if UVLOOP_DEBUG:
-assert arr_len >0
-
  ret =<char**>PyMem_RawMalloc((arr_len +1) * sizeof(char*))
 if ret isNULL:
 raiseMemoryError()
@@ -285,7 +282,7 @@ cdef class UVProcess(UVHandle):
 self.uv_opt_args =self.__to_cstring_array(self.__args)
 
  cdef _init_env(self, dict env):
-if env isnotNoneandlen(env):
+if env isnotNone:
 self.__env =list()
 for key in env:
  val = env[key]