From 19d5d3b7d185dd42521b062b135e14c08732d5f6 Mon Sep 17 00:00:00 2001
From: Ben Gotow <bengotow@gmail.com>
Date: Sat, 7 May 2016 11:07:58 -0700
Subject: [PATCH 1/2] Implement RemoveAsDefaultProtocolClient on OS X

---
 atom/browser/browser_mac.mm | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/atom/browser/browser_mac.mm b/atom/browser/browser_mac.mm
index eb7191b67a2..767ddee590e 100644
--- a/atom/browser/browser_mac.mm
+++ b/atom/browser/browser_mac.mm
@@ -43,7 +43,28 @@ void Browser::ClearRecentDocuments() {
 }
 
 bool Browser::RemoveAsDefaultProtocolClient(const std::string& protocol) {
-  return false;
+  NSString* identifier = [base::mac::MainBundle() bundleIdentifier];
+  if (!identifier)
+    return false;
+
+  NSString* protocol_ns = [NSString stringWithUTF8String:protocol.c_str()];
+  CFStringRef protocol_cf = base::mac::NSToCFCast(protocol_ns);
+  CFArrayRef bundleList = LSCopyAllHandlersForURLScheme(protocol_cf);
+  if (!bundleList) {
+    return false;
+  }
+  // On Mac OS X, we can't query the default, but the handlers list seems to put
+  // Apple's defaults first, so we'll use the first option that isn't our bundle
+  CFStringRef other = nil;
+  for (CFIndex i = 0; i < CFArrayGetCount(bundleList); i++) {
+    other = (CFStringRef)CFArrayGetValueAtIndex(bundleList, i);
+    if (![identifier isEqualToString: (__bridge NSString *)other]) {
+      break;
+    }
+  }
+
+  OSStatus return_code = LSSetDefaultHandlerForURLScheme(protocol_cf, other);
+  return return_code == noErr;
 }
 
 bool Browser::SetAsDefaultProtocolClient(const std::string& protocol) {

From ac905e708009d17cf048c296e802f68c21a6a721 Mon Sep 17 00:00:00 2001
From: Ben Gotow <bengotow@gmail.com>
Date: Sun, 8 May 2016 10:50:17 -0700
Subject: [PATCH 2/2] Add docs, avoid side effects when not currently default

---
 atom/browser/browser_mac.mm | 3 +++
 docs/api/app.md             | 5 +----
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/atom/browser/browser_mac.mm b/atom/browser/browser_mac.mm
index 767ddee590e..3cabd98b692 100644
--- a/atom/browser/browser_mac.mm
+++ b/atom/browser/browser_mac.mm
@@ -47,6 +47,9 @@ bool Browser::RemoveAsDefaultProtocolClient(const std::string& protocol) {
   if (!identifier)
     return false;
 
+  if (!Browser::IsDefaultProtocolClient(protocol))
+    return false;
+
   NSString* protocol_ns = [NSString stringWithUTF8String:protocol.c_str()];
   CFStringRef protocol_cf = base::mac::NSToCFCast(protocol_ns);
   CFArrayRef bundleList = LSCopyAllHandlersForURLScheme(protocol_cf);
diff --git a/docs/api/app.md b/docs/api/app.md
index c6c5887ef62..cb19b49b7c1 100644
--- a/docs/api/app.md
+++ b/docs/api/app.md
@@ -393,16 +393,13 @@ Please refer to [Apple's documentation][CFBundleURLTypes] for details.
 
 The API uses the Windows Registry and LSSetDefaultHandlerForURLScheme internally.
 
-### `app.removeAsDefaultProtocolClient(protocol)` _Windows_
+### `app.removeAsDefaultProtocolClient(protocol)` _OS X_ _Windows_
 
 * `protocol` String - The name of your protocol, without `://`.
 
 This method checks if the current executable as the default handler for a protocol
 (aka URI scheme). If so, it will remove the app as the default handler.
 
-**Note:** On OS X, removing the app will automatically remove the app as the
-default protocol handler.
-
 ### `app.isDefaultProtocolClient(protocol)` _OS X_ _Windows_
 
 * `protocol` String - The name of your protocol, without `://`.