test-runner: fix process output truncation

There was a bug with process output where the last bit of data would
never make it into stdout or log files. This was due to the IO watch
being cleaned up when the process was killed and never allowing it
to finish writing any pending data.

Now the IO watch implementation has been moved out into its own
function (io_process) which is now used to write the final bits of
data out on process exit.

tools/test-runner

@@ -244,31 +244,22 @@ class Process:
 
 		self.pid.wait(timeout=5)
 		self.killed = True
+		self.ret = self.pid.returncode
 
 		self.stdout.seek(self.io_position)
 		self.out = self.stdout.read()
 		self.stdout.seek(0, 2)
-		self.ret = self.pid.returncode
 
-		#
-		# No IO callback for wait/check=True processes so write out
-		# the data to any FD's now.
-		#
 		if len(self.write_fds) > 0:
-			for fd in self.write_fds:
-				fd.write(self.out)
-				fd.close()
+			self.process_io(self.stdout)
 
-			self.write_fds = []
-
-		if self.verbose:
-			sys.__stdout__.write(self.out)
+		self.write_fds = []
 
 		print("%s returned %d" % (args[0], self.ret))
 		if check and self.ret != 0:
 			raise subprocess.CalledProcessError(returncode=self.ret, cmd=self.args)
 
-	def io_callback(self, source, cb_condition):
+	def process_io(self, source):
 		#
 		# The file will have already been written to, meaning the seek
 		# position points to EOF. This is why the position is saved so
@@ -286,20 +277,27 @@ class Process:
 
 		for f in self.write_fds:
 			f.write(data)
+			f.flush()
 
 		if self.verbose:
 			sys.__stdout__.write(data)
+			sys.__stdout__.flush()
 
 		return True
 
+	def io_callback(self, source, cb_condition):
+		return self.process_io(source)
+
 	def __del__(self):
 		print("Del process %s" % self.args)
 
+		os.remove(self.output_name)
+
+		self.stdout.close()
+
 		if not self.killed:
 			self.kill()
 
-		os.remove(self.output_name)
-
 	def kill(self, force=False):
 		print("Killing process %s" % self.args)
 
@@ -319,8 +317,10 @@ class Process:
 
 		self.ctx = None
 
-		for f in self.write_fds:
-			f.close()
+		self.process_io(self.stdout)
+
+		if self.cleanup:
+			self.cleanup()
 
 		self.write_fds = []
 
@@ -328,13 +328,7 @@ class Process:
 			GLib.source_remove(self.io_watch)
 			self.io_watch = None
 
-		if self.cleanup:
-			self.cleanup()
-
 		self.cleanup = None
-
-		self.stdout.close()
-
 		self.killed = True
 
 	def wait_for_socket(self, socket, wait):