macos: inject CFBundleIdentifier in subprocess before MachPortRendezvous lookup

CEF 130+ builds the MachPortRendezvousClient service name as:
  CFBundleIdentifier + ".MachPortRendezvousServer." + parent_pid

The browser process injects CFBundleIdentifier = "org.cefpython" via
MacInitialize() in util_mac.mm before CefInitialize(), so it registers:
  "org.cefpython.MachPortRendezvousServer.<pid>"

The subprocess binary is a flat binary (not in an app bundle), so
CFBundleGetMainBundle() returns no CFBundleIdentifier and the client
looks up ".MachPortRendezvousServer.<parent_pid>" — a name starting with
"." that bootstrap_look_up can never find (BOOTSTRAP_UNKNOWN_SERVICE 1102).
This caused every spawned subprocess to terminate immediately with
"No rendezvous client, terminating process (parent died?)".

Fix: add main_mac.mm (compiled only on Apple) which injects the same
"org.cefpython" bundle identifier into the subprocess's main bundle dict
before CefExecuteProcess runs, matching what the parent registered.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: linesight

src/subprocess/main.cpp

@@ -30,6 +30,18 @@ int APIENTRY wWinMain(HINSTANCE hInstance,
 
 int main(int argc, char **argv)
 {
+#if defined(OS_MAC)
+	// CEF 130+: MachPortRendezvousClientMac builds the service name as
+	//   CFBundleIdentifier + ".MachPortRendezvousServer." + parent_pid
+	// The browser process injects CFBundleIdentifier = "org.cefpython" in
+	// MacInitialize() before CefInitialize().  This subprocess binary is a flat
+	// binary (not an app bundle), so CFBundleGetMainBundle() returns no
+	// CFBundleIdentifier, producing a lookup name starting with "." that never
+	// matches the registered service.  Call SubprocessMacInit() to inject the
+	// same identifier so bootstrap_look_up finds the server.
+	extern "C" void SubprocessMacInit();
+	SubprocessMacInit();
+#endif
 #if defined(OS_LINUX)
 	// Chrome 130+ passes --pseudonymization-salt-handle to directly-launched
 	// (non-zygote) subprocesses, expecting GlobalDescriptors[key] to be

src/subprocess/main_mac.mm

@@ -0,0 +1,32 @@
+// Copyright (c) 2025 CEF Python, see the Authors file.
+// All rights reserved. Licensed under BSD 3-clause license.
+// Project website: https://github.com/cztomczak/cefpython
+
+#import <CoreFoundation/CoreFoundation.h>
+
+// Called from main.cpp before CefExecuteProcess on macOS.
+//
+// CEF 130+ builds the MachPortRendezvousClient lookup name as:
+//   CFBundleIdentifier + ".MachPortRendezvousServer." + parent_pid
+//
+// The parent (browser process) has CFBundleIdentifier = "org.cefpython"
+// injected in util_mac.mm / MacInitialize().  The subprocess is a flat
+// binary without an app bundle, so CFBundleGetMainBundle() returns no
+// CFBundleIdentifier and the lookup name starts with ".", which never
+// matches the registered service name.  Inject the same identifier here
+// so both sides agree and bootstrap_look_up succeeds.
+extern "C" void SubprocessMacInit() {
+    CFBundleRef mainBundle = CFBundleGetMainBundle();
+    if (mainBundle) {
+        CFStringRef bundleID = CFBundleGetIdentifier(mainBundle);
+        if (!bundleID || CFStringGetLength(bundleID) == 0) {
+            CFMutableDictionaryRef infoDict =
+                (CFMutableDictionaryRef)CFBundleGetInfoDictionary(mainBundle);
+            if (infoDict) {
+                CFDictionarySetValue(infoDict,
+                                     CFSTR("CFBundleIdentifier"),
+                                     CFSTR("org.cefpython"));
+            }
+        }
+    }
+}