From ceb740f709a1490c6a2fffe1c42b0e743232dbba Mon Sep 17 00:00:00 2001
From: Robert Sesek <rsesek@bluestatic.org>
Date: Sun, 13 Mar 2016 19:15:16 -0400
Subject: [PATCH] Creating an IOServiceIterator could have a 0 value, confused
 for failure.

Instead, return bool and use an out pointer for the iterator.
---
 apple-ir-control.cc | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/apple-ir-control.cc b/apple-ir-control.cc
index 337a457..a48d7e1 100644
--- a/apple-ir-control.cc
+++ b/apple-ir-control.cc
@@ -111,16 +111,15 @@ bool SynchronizePrefs() {
   return rv;
 }
 
-io_iterator_t CreateIOServiceIterator() {
+bool CreateIOServiceIterator(io_iterator_t* iterator) {
   CFMutableDictionaryRef matching_dict = IOServiceMatching("AppleIRController");
-  io_iterator_t iterator;
   kern_return_t kr = IOServiceGetMatchingServices(
-      kIOMasterPortDefault, matching_dict, &iterator);
+      kIOMasterPortDefault, matching_dict, iterator);
   if (kr != KERN_SUCCESS) {
     ERROR("Failed to IOServiceGetMatchingServices: 0x%x", kr);
-    return 0;
+    return false;
   }
-  return iterator;
+  return true;;
 }
 
 int HandleRead() {
@@ -128,8 +127,8 @@ int HandleRead() {
       kCFPreferencesAnyUser, kCFPreferencesCurrentHost);
   printf("Userspace property value: %s\n", GetBooleanDescription(user_prop));
 
-  io_iterator_t iterator = CreateIOServiceIterator();
-  if (!iterator)
+  io_iterator_t iterator;
+  if (!CreateIOServiceIterator(&iterator))
     return EXIT_FAILURE;
 
   io_object_t service;
@@ -153,7 +152,7 @@ int HandleRead() {
   }
 
   if (!did_find) {
-    ERROR("Failed to match AppleIRController");
+    ERROR("Failed to match any AppleIRController");
     return EXIT_FAILURE;
   }
 
@@ -173,7 +172,10 @@ int HandleWrite(bool enable) {
   if (!SynchronizePrefs())
     return EXIT_FAILURE;
 
-  io_iterator_t iterator = CreateIOServiceIterator();
+  io_iterator_t iterator;
+  if (!CreateIOServiceIterator(&iterator))
+    return EXIT_FAILURE;
+
   io_object_t service;
   while ((service = IOIteratorNext(iterator))) {
     io_name_t name;
-- 
2.22.5