darling-lol/patches/corefoundation.patch

diff --git a/CFError.c b/CFError.c
index 91b5a2b..0f7b4eb 100644
--- a/CFError.c
+++ b/CFError.c
@@ -30,6 +30,7 @@
 #include <CoreFoundation/CFError_Private.h>
 #include "CFInternal.h"
 #include <CoreFoundation/CFPriv.h>
+#include <sys/mman.h> /* darling-lol: mincore for isa validation */
 #if DEPLOYMENT_TARGET_MACOSX || DEPLOYMENT_TARGET_EMBEDDED
 #include <mach/mach_error.h>
 #endif
@@ -380,6 +381,19 @@ CFDictionaryRef CFErrorCopyUserInfo(CFErrorRef err) {
 }
 
 CFStringRef CFErrorCopyDescription(CFErrorRef err) {
+#ifdef DARLING
+    /* Fail soft on NULL/unmapped-isa errors: callers (and some Darling
+     * stubs that fail without setting out-errors) can hand us garbage;
+     * the description is logging-only, crashing here helps nothing. */
+    if (!err)
+        return CFSTR("(null error)");
+    {
+        uintptr_t isa = ((CFRuntimeBase *)err)->_cfisa;
+        char vec = 0;
+        if (isa == 0 || mincore((void *)(isa & ~0xFFFUL), 4096, &vec) != 0)
+            return CFSTR("(null error)");
+    }
+#endif
     if (CF_IS_OBJC(CFErrorGetTypeID(), err)) {  // Since we have to return a retained result, we need to treat the toll-free bridging specially
         CFStringRef desc = (CFStringRef) CF_OBJC_CALLV((NSError *)err, localizedDescription);
         return desc ? (CFStringRef)CFRetain(desc) : NULL;    // !!! It really should never return nil.
@@ -389,6 +403,19 @@ CFStringRef CFErrorCopyDescription(CFErrorRef err) {
 }
 
 CFStringRef CFErrorCopyFailureReason(CFErrorRef err) {
+#ifdef DARLING
+    /* Fail soft on NULL/unmapped-isa errors: callers (and some Darling
+     * stubs that fail without setting out-errors) can hand us garbage;
+     * the description is logging-only, crashing here helps nothing. */
+    if (!err)
+        return CFSTR("(null error)");
+    {
+        uintptr_t isa = ((CFRuntimeBase *)err)->_cfisa;
+        char vec = 0;
+        if (isa == 0 || mincore((void *)(isa & ~0xFFFUL), 4096, &vec) != 0)
+            return CFSTR("(null error)");
+    }
+#endif
     if (CF_IS_OBJC(CFErrorGetTypeID(), err)) {  // Since we have to return a retained result, we need to treat the toll-free bridging specially
         CFStringRef str = (CFStringRef) CF_OBJC_CALLV((NSError *)err, localizedFailureReason);
         return str ? (CFStringRef)CFRetain(str) : NULL;    // It's possible for localizedFailureReason to return nil
@@ -398,6 +425,19 @@ CFStringRef CFErrorCopyFailureReason(CFErrorRef err) {
 }
 
 CFStringRef CFErrorCopyRecoverySuggestion(CFErrorRef err) {
+#ifdef DARLING
+    /* Fail soft on NULL/unmapped-isa errors: callers (and some Darling
+     * stubs that fail without setting out-errors) can hand us garbage;
+     * the description is logging-only, crashing here helps nothing. */
+    if (!err)
+        return CFSTR("(null error)");
+    {
+        uintptr_t isa = ((CFRuntimeBase *)err)->_cfisa;
+        char vec = 0;
+        if (isa == 0 || mincore((void *)(isa & ~0xFFFUL), 4096, &vec) != 0)
+            return CFSTR("(null error)");
+    }
+#endif
     if (CF_IS_OBJC(CFErrorGetTypeID(), err)) {  // Since we have to return a retained result, we need to treat the toll-free bridging specially
         CFStringRef str = (CFStringRef) CF_OBJC_CALLV((NSError *)err, localizedRecoverySuggestion);
         return str ? (CFStringRef)CFRetain(str) : NULL;    // It's possible for localizedRecoverySuggestion to return nil
diff --git a/CFRunLoop.c b/CFRunLoop.c
index e932ea5..522bc72 100644
--- a/CFRunLoop.c
+++ b/CFRunLoop.c
@@ -27,6 +27,7 @@
 */
 
 #include <CoreFoundation/CFRunLoop.h>
+extern int __simple_printf(const char *, ...); /* darling-lol M58F20 */
 #include <CoreFoundation/CFSet.h>
 #include <CoreFoundation/CFBag.h>
 #include <CoreFoundation/CFNumber.h>
@@ -38,6 +39,14 @@
 #include <pthread.h>
 #include <dispatch/dispatch.h>
 
+/* Opt-in bounded idle waits while investigating lost Mach run-loop wakeups.
+ * Read configuration at load time, never from syscall wrappers. */
+static Boolean darlingBoundedRunLoopWait;
+__attribute__((constructor)) static void darlingConfigureRunLoopWait(void) {
+    const char *value = getenv("RCLOL_CF_POLL");
+    darlingBoundedRunLoopWait = value && value[0] == '1';
+}
+
 
 #if DEPLOYMENT_TARGET_WINDOWS
 #include <typeinfo.h>
@@ -2209,6 +2218,8 @@ static int32_t __CFRunLoopRun(CFRunLoopRef rl, CFRunLoopModeRef rlm, CFTimeInter
 #define TIMEOUT_INFINITY (~(mach_msg_timeout_t)0)
 
 static Boolean __CFRunLoopServiceMachPort(mach_port_name_t port, mach_msg_header_t **buffer, size_t buffer_size, mach_port_t *livePort, mach_msg_timeout_t timeout, voucher_mach_msg_state_t *voucherState, voucher_t *voucherCopy) {
+    if (darlingBoundedRunLoopWait && timeout == TIMEOUT_INFINITY)
+        timeout = 10;
     Boolean originalBuffer = true;
     kern_return_t ret = KERN_SUCCESS;
     for (;;) {		/* In that sleep of death what nightmares may come ... */
@@ -2417,6 +2428,11 @@ static int32_t __CFRunLoopRun(CFRunLoopRef rl, CFRunLoopModeRef rlm, CFTimeInter
 
         Boolean poll = sourceHandledThisLoop || (0ULL == timeout_context->termTSR);
 
+        // darling-lol: every Mach port-set change and receive is a synchronous round trip to darlingserver here.
+        // A zero-timeout pass that has just polled the dispatch port on its own does not need to put that same
+        // port into the wait set (insert) and take it out again (extract) around the non-blocking set poll: a
+        // message that lands in between is picked up by the very next pass.
+        Boolean darlingSkipDispatchSet = poll && (MACH_PORT_NULL != dispatchPort) && !didDispatchPortLastTime;
         if (MACH_PORT_NULL != dispatchPort && !didDispatchPortLastTime) {
 #if DEPLOYMENT_TARGET_MACOSX || DEPLOYMENT_TARGET_EMBEDDED || DEPLOYMENT_TARGET_EMBEDDED_MINI
             msg = (mach_msg_header_t *)msg_buffer;
@@ -2440,7 +2456,7 @@ static int32_t __CFRunLoopRun(CFRunLoopRef rl, CFRunLoopModeRef rlm, CFTimeInter
         // iteration, as this mode could be run re-entrantly and we don't
         // want these ports to get serviced.
 
-        __CFPortSetInsert(dispatchPort, waitSet);
+        if (!darlingSkipDispatchSet) __CFPortSetInsert(dispatchPort, waitSet);
         
 	__CFRunLoopModeUnlock(rlm);
 	__CFRunLoopUnlock(rl);
@@ -2500,7 +2516,7 @@ static int32_t __CFRunLoopRun(CFRunLoopRef rl, CFRunLoopModeRef rlm, CFTimeInter
         // want these ports to get serviced. Also, we don't want them left
         // in there if this function returns.
 
-        __CFPortSetRemove(dispatchPort, waitSet);
+        if (!darlingSkipDispatchSet) __CFPortSetRemove(dispatchPort, waitSet);
         
         __CFRunLoopSetIgnoreWakeUps(rl);
 
@@ -2550,7 +2566,11 @@ static int32_t __CFRunLoopRun(CFRunLoopRef rl, CFRunLoopModeRef rlm, CFTimeInter
 #endif
         if (MACH_PORT_NULL == livePort) {
             CFRUNLOOP_WAKEUP_FOR_NOTHING();
-            // handle nothing
+            /* A bounded wait or zero-timeout poll must check due timers when
+             * their Mach notification was missed. Otherwise AppKit observes
+             * an overdue timer, skips its idle wait, and polls forever. */
+            if (darlingBoundedRunLoopWait || poll)
+                __CFRunLoopDoTimers(rl, rlm, mach_absolute_time());
         } else if (livePort == rl->_wakeUpPort) {
             CFRUNLOOP_WAKEUP_FOR_WAKEUP();
             // do nothing on Mac OS
@@ -2719,21 +2739,46 @@ void CFRunLoopWakeUp(CFRunLoopRef rl) {
     CHECK_FOR_FORK();
     // This lock is crucial to ignorable wakeups, do not remove it.
     __CFRunLoopLock(rl);
+    /* darling-lol M58F32: do NOT drop the wakeup when ignoreWakeUps is set.
+     *
+     * The upstream guard skips sending the wake while the runloop is in its
+     * post-wait "handling" phase (flag set at CFRunLoop.c ~2514/2521, cleared
+     * only before the next Mach wait at ~2400).  On macOS that window is short,
+     * so a skipped wake is harmless - the runloop is already awake and about to
+     * run its sources.  Under Darling the browser main thread's handling phase
+     * can be very long (the browser loop runs seconds-late/starves; see the
+     * M58n/M58o/M58ad findings).  In that state a cross-thread PostTask onto the
+     * main thread's TASK_ENVIRONMENT_DEFAULT_TQ schedules exactly this wake, and
+     * dropping it means the queued task is not noticed until the runloop next
+     * parks and an unrelated event wakes it - which is the observed black-window
+     * defect (M58f25: no WAKE_SEND at the notification moment; M58f31: 6 dropped
+     * wakes on the CrBrowserMain runloop).
+     *
+     * The send is deliberately unconditional below ("we don't want to lose a
+     * wakeup"), and the wake-up port queue length is 1, so an extra wake while
+     * handling is harmless (it coalesces).  We therefore fall through to send it
+     * even when the flag is set, instead of returning early. */
+#if 0
     if (__CFRunLoopIsIgnoringWakeUps(rl)) {
         __CFRunLoopUnlock(rl);
         return;
     }
+#endif
 #if DEPLOYMENT_TARGET_MACOSX || DEPLOYMENT_TARGET_EMBEDDED || DEPLOYMENT_TARGET_EMBEDDED_MINI
     kern_return_t ret;
     /* We unconditionally try to send the message, since we don't want
      * to lose a wakeup, but the send may fail if there is already a
      * wakeup pending, since the queue length is 1. */
-    ret = __CFSendTrivialMachMessage(rl->_wakeUpPort, 0, MACH_SEND_TIMEOUT, 0);
+    /* darling-lol: the send is a darlingserver round trip (~50 us); do it after dropping the run loop lock so other
+     * threads (including the run loop's own thread) do not block on the lock for the duration of the RPC. */
+    mach_port_t wakePort = rl->_wakeUpPort;
+    __CFRunLoopUnlock(rl);
+    ret = __CFSendTrivialMachMessage(wakePort, 0, MACH_SEND_TIMEOUT, 0);
     if (ret != MACH_MSG_SUCCESS && ret != MACH_SEND_TIMED_OUT) CRASH("*** Unable to send message to wake up port. (%d) ***", ret);
 #elif DEPLOYMENT_TARGET_WINDOWS
     SetEvent(rl->_wakeUpPort);
-#endif
     __CFRunLoopUnlock(rl);
+#endif
 }
 
 void CFRunLoopStop(CFRunLoopRef rl) {
@@ -2828,6 +2873,10 @@ void CFRunLoopPerformBlock(CFRunLoopRef rl, CFTypeRef mode, void (^block)(void))
 
 Boolean CFRunLoopContainsSource(CFRunLoopRef rl, CFRunLoopSourceRef rls, CFStringRef modeName) {
     CHECK_FOR_FORK();
+#ifdef DARLING
+    /* See CFRunLoopAddSource: NULL sources are never contained. */
+    if (NULL == rls) return false;
+#endif
     CFRunLoopModeRef rlm;
     Boolean hasValue = false;
     __CFRunLoopLock(rl);
@@ -2849,6 +2898,13 @@ Boolean CFRunLoopContainsSource(CFRunLoopRef rl, CFRunLoopSourceRef rls, CFStrin
 void CFRunLoopAddSource(CFRunLoopRef rl, CFRunLoopSourceRef rls, CFStringRef modeName) {	/* DOES CALLOUT */
     CHECK_FOR_FORK();
     if (__CFRunLoopIsDeallocating(rl)) return;
+#ifdef DARLING
+    /* Darling's IOKit has no iokitd, so notification-port lookups can
+     * legitimately yield NULL where Apple always returns a port.
+     * Ignore NULL sources instead of crashing (matches the fail-soft
+     * guards in IOKitUser). */
+    if (NULL == rls) return;
+#endif
     if (!__CFIsValid(rls)) return;
     Boolean doVer0Callout = false;
     __CFRunLoopLock(rl);
@@ -2910,6 +2966,10 @@ void CFRunLoopAddSource(CFRunLoopRef rl, CFRunLoopSourceRef rls, CFStringRef mod
 
 void CFRunLoopRemoveSource(CFRunLoopRef rl, CFRunLoopSourceRef rls, CFStringRef modeName) {	/* DOES CALLOUT */
     CHECK_FOR_FORK();
+#ifdef DARLING
+    /* See CFRunLoopAddSource: ignore NULL sources. */
+    if (NULL == rls) return;
+#endif
     Boolean doVer0Callout = false, doRLSRelease = false;
     __CFRunLoopLock(rl);
     if (modeName == kCFRunLoopCommonModes) {
@@ -3432,6 +3492,12 @@ void CFRunLoopSourceSignal(CFRunLoopSourceRef rls) {
 	__CFRunLoopSourceSetSignaled(rls);
     }
     __CFRunLoopSourceUnlock(rls);
+    #if 0 /* darling-lol: keep hot source-signal tracing off by default. */
+    { /* darling-lol M58F25: source-signal trace (bounded) */
+        static unsigned long _m58f25 = 0;
+        if (_m58f25++ < 4000) __simple_printf("M58F25 SIG_SRC rls=%p tid=0x%x\n", (void*)rls, (unsigned)pthread_mach_thread_np(pthread_self()));
+    }
+    #endif
 }
 
 Boolean CFRunLoopSourceIsSignalled(CFRunLoopSourceRef rls) {
@@ -3966,4 +4032,3 @@ void CFRunLoopTimerSetTolerance(CFRunLoopTimerRef rlt, CFTimeInterval tolerance)
     }
 #endif
 }
-
diff --git a/CFString.c b/CFString.c
index 162403a..b9ad8a0 100644
--- a/CFString.c
+++ b/CFString.c
@@ -6572,3 +6572,24 @@ void CFShowStr(CFStringRef str) {
 #undef HANGUL_TCOUNT
 #undef HANGUL_NCOUNT
 
+
+/* Darling has no locale hyphenation dictionaries. Advertise that capability
+ * truthfully instead of leaving the macOS APIs absent (which aborts callers
+ * at lazy symbol binding). Ordinary line wrapping remains available. */
+Boolean CFStringIsHyphenationAvailableForLocale(CFLocaleRef locale) {
+    (void)locale;
+    return false;
+}
+
+CFIndex CFStringGetHyphenationLocationBeforeIndex(CFStringRef string,
+        CFIndex location, CFRange limitRange, CFOptionFlags options,
+        CFLocaleRef locale, UTF32Char *character) {
+    (void)string;
+    (void)location;
+    (void)limitRange;
+    (void)options;
+    (void)locale;
+    if (character != NULL)
+        *character = 0;
+    return kCFNotFound;
+}
diff --git a/NSArray.m b/NSArray.m
index 30ac9df..b389210 100644
--- a/NSArray.m
+++ b/NSArray.m
@@ -1232,6 +1232,15 @@ SINGLETON_RR()
     return success;
 }
 
+- (BOOL)writeToURL:(NSURL *)url error:(NSError **)error
+{
+    BOOL success = [self writeToURL:url atomically:YES];
+    if (!success && error != NULL) {
+        *error = [NSError errorWithDomain:NSCocoaErrorDomain code:NSFileWriteUnknownError userInfo:nil];
+    }
+    return success;
+}
+
 - (void)makeObjectsPerformSelector:(SEL)sel
 {
     [self makeObjectsPerformSelector:sel withObject:nil];
diff --git a/NSDictionary.m b/NSDictionary.m
index a3da56a..4678733 100644
--- a/NSDictionary.m
+++ b/NSDictionary.m
@@ -986,6 +986,15 @@ static NSString *_getDescription(id obj, id locale, int level)
     return success;
 }
 
+- (BOOL)writeToURL:(NSURL *)url error:(NSError **)error
+{
+    BOOL success = [self writeToURL:url atomically:YES];
+    if (!success && error != NULL) {
+        *error = [NSError errorWithDomain:NSCocoaErrorDomain code:NSFileWriteUnknownError userInfo:nil];
+    }
+    return success;
+}
+
 - (NSArray *)keysSortedByValueUsingSelector:(SEL)comparator
 {
     return [[self allKeys] sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {