1 files changed, 105 insertions, 19 deletions

diff --git a/compat/fsmonitor/fsm-listen-darwin.c b/compat/fsmonitor/fsm-listen-darwin.c
index 0741fe8..8e208e8 100644
--- a/compat/fsmonitor/fsm-listen-darwin.c
+++ b/compat/fsmonitor/fsm-listen-darwin.c
@@ -27,7 +27,7 @@
 #include "fsm-listen.h"
 #include "fsmonitor--daemon.h"
 
-struct fsmonitor_daemon_backend_data
+struct fsm_listen_data
 {
 	CFStringRef cfsr_worktree_path;
 	CFStringRef cfsr_gitdir_path;
@@ -100,12 +100,17 @@ static void log_flags_set(const char *path, const FSEventStreamEventFlags flag)
 	if (flag & kFSEventStreamEventFlagItemCloned)
 		strbuf_addstr(&msg, "ItemCloned|");
 
-	trace_printf_key(&trace_fsmonitor, "fsevent: '%s', flags=%u %s",
+	trace_printf_key(&trace_fsmonitor, "fsevent: '%s', flags=0x%x %s",
 			 path, flag, msg.buf);
 
 	strbuf_release(&msg);
 }
 
+static int ef_is_root_changed(const FSEventStreamEventFlags ef)
+{
+	return (ef & kFSEventStreamEventFlagRootChanged);
+}
+
 static int ef_is_root_delete(const FSEventStreamEventFlags ef)
 {
 	return (ef & kFSEventStreamEventFlagItemIsDir &&
@@ -125,6 +130,60 @@ static int ef_is_dropped(const FSEventStreamEventFlags ef)
 		ef & kFSEventStreamEventFlagUserDropped);
 }
 
+/*
+ * If an `xattr` change is the only reason we received this event,
+ * then silently ignore it.  Git doesn't care about xattr's.  We
+ * have to be careful here because the kernel can combine multiple
+ * events for a single path.  And because events always have certain
+ * bits set, such as `ItemIsFile` or `ItemIsDir`.
+ *
+ * Return 1 if we should ignore it.
+ */
+static int ef_ignore_xattr(const FSEventStreamEventFlags ef)
+{
+	static const FSEventStreamEventFlags mask =
+		kFSEventStreamEventFlagItemChangeOwner |
+		kFSEventStreamEventFlagItemCreated |
+		kFSEventStreamEventFlagItemFinderInfoMod |
+		kFSEventStreamEventFlagItemInodeMetaMod |
+		kFSEventStreamEventFlagItemModified |
+		kFSEventStreamEventFlagItemRemoved |
+		kFSEventStreamEventFlagItemRenamed |
+		kFSEventStreamEventFlagItemXattrMod |
+		kFSEventStreamEventFlagItemCloned;
+
+	return ((ef & mask) == kFSEventStreamEventFlagItemXattrMod);
+}
+
+/*
+ * On MacOS we have to adjust for Unicode composition insensitivity
+ * (where NFC and NFD spellings are not respected).  The different
+ * spellings are essentially aliases regardless of how the path is
+ * actually stored on the disk.
+ *
+ * This is related to "core.precomposeUnicode" (which wants to try
+ * to hide NFD completely and treat everything as NFC).  Here, we
+ * don't know what the value the client has (or will have) for this
+ * config setting when they make a query, so assume the worst and
+ * emit both when the OS gives us an NFD path.
+ */
+static void my_add_path(struct fsmonitor_batch *batch, const char *path)
+{
+	char *composed;
+
+	/* add the NFC or NFD path as received from the OS */
+	fsmonitor_batch__add_path(batch, path);
+
+	/* if NFD, also add the corresponding NFC spelling */
+	composed = (char *)precompose_string_if_needed(path);
+	if (!composed || composed == path)
+		return;
+
+	fsmonitor_batch__add_path(batch, composed);
+	free(composed);
+}
+
+
 static void fsevent_callback(ConstFSEventStreamRef streamRef,
 			     void *ctx,
 			     size_t num_of_events,
@@ -133,7 +192,7 @@ static void fsevent_callback(ConstFSEventStreamRef streamRef,
 			     const FSEventStreamEventId event_ids[])
 {
 	struct fsmonitor_daemon_state *state = ctx;
-	struct fsmonitor_daemon_backend_data *data = state->backend_data;
+	struct fsm_listen_data *data = state->listen_data;
 	char **paths = (char **)event_paths;
 	struct fsmonitor_batch *batch = NULL;
 	struct string_list cookie_list = STRING_LIST_INIT_DUP;
@@ -190,6 +249,33 @@ static void fsevent_callback(ConstFSEventStreamRef streamRef,
 			continue;
 		}
 
+		if (ef_is_root_changed(event_flags[k])) {
+			/*
+			 * The spelling of the pathname of the root directory
+			 * has changed.  This includes the name of the root
+			 * directory itself or of any parent directory in the
+			 * path.
+			 *
+			 * (There may be other conditions that throw this,
+			 * but I couldn't find any information on it.)
+			 *
+			 * Force a shutdown now and avoid things getting
+			 * out of sync.  The Unix domain socket is inside
+			 * the .git directory and a spelling change will make
+			 * it hard for clients to rendezvous with us.
+			 */
+			trace_printf_key(&trace_fsmonitor,
+					 "event: root changed");
+			goto force_shutdown;
+		}
+
+		if (ef_ignore_xattr(event_flags[k])) {
+			trace_printf_key(&trace_fsmonitor,
+					 "ignore-xattr: '%s', flags=0x%x",
+					 path_k, event_flags[k]);
+			continue;
+		}
+
 		switch (fsmonitor_classify_path_absolute(state, path_k)) {
 
 		case IS_INSIDE_DOT_GIT_WITH_COOKIE_PREFIX:
@@ -248,7 +334,7 @@ static void fsevent_callback(ConstFSEventStreamRef streamRef,
 
 				if (!batch)
 					batch = fsmonitor_batch__new();
-				fsmonitor_batch__add_path(batch, rel);
+				my_add_path(batch, rel);
 			}
 
 			if (event_flags[k] & kFSEventStreamEventFlagItemIsDir) {
@@ -261,7 +347,7 @@ static void fsevent_callback(ConstFSEventStreamRef streamRef,
 
 				if (!batch)
 					batch = fsmonitor_batch__new();
-				fsmonitor_batch__add_path(batch, tmp.buf);
+				my_add_path(batch, tmp.buf);
 			}
 
 			break;
@@ -318,11 +404,11 @@ int fsm_listen__ctor(struct fsmonitor_daemon_state *state)
 		NULL,
 		NULL
 	};
-	struct fsmonitor_daemon_backend_data *data;
+	struct fsm_listen_data *data;
 	const void *dir_array[2];
 
 	CALLOC_ARRAY(data, 1);
-	state->backend_data = data;
+	state->listen_data = data;
 
 	data->cfsr_worktree_path = CFStringCreateWithCString(
 		NULL, state->path_worktree_watch.buf, kCFStringEncodingUTF8);
@@ -342,7 +428,7 @@ int fsm_listen__ctor(struct fsmonitor_daemon_state *state)
 					   data->cfar_paths_to_watch,
 					   kFSEventStreamEventIdSinceNow,
 					   0.001, flags);
-	if (data->stream == NULL)
+	if (!data->stream)
 		goto failed;
 
 	/*
@@ -354,18 +440,18 @@ int fsm_listen__ctor(struct fsmonitor_daemon_state *state)
 failed:
 	error(_("Unable to create FSEventStream."));
 
-	FREE_AND_NULL(state->backend_data);
+	FREE_AND_NULL(state->listen_data);
 	return -1;
 }
 
 void fsm_listen__dtor(struct fsmonitor_daemon_state *state)
 {
-	struct fsmonitor_daemon_backend_data *data;
+	struct fsm_listen_data *data;
 
-	if (!state || !state->backend_data)
+	if (!state || !state->listen_data)
 		return;
 
-	data = state->backend_data;
+	data = state->listen_data;
 
 	if (data->stream) {
 		if (data->stream_started)
@@ -375,14 +461,14 @@ void fsm_listen__dtor(struct fsmonitor_daemon_state *state)
 		FSEventStreamRelease(data->stream);
 	}
 
-	FREE_AND_NULL(state->backend_data);
+	FREE_AND_NULL(state->listen_data);
 }
 
 void fsm_listen__stop_async(struct fsmonitor_daemon_state *state)
 {
-	struct fsmonitor_daemon_backend_data *data;
+	struct fsm_listen_data *data;
 
-	data = state->backend_data;
+	data = state->listen_data;
 	data->shutdown_style = SHUTDOWN_EVENT;
 
 	CFRunLoopStop(data->rl);
@@ -390,9 +476,9 @@ void fsm_listen__stop_async(struct fsmonitor_daemon_state *state)
 
 void fsm_listen__loop(struct fsmonitor_daemon_state *state)
 {
-	struct fsmonitor_daemon_backend_data *data;
+	struct fsm_listen_data *data;
 
-	data = state->backend_data;
+	data = state->listen_data;
 
 	data->rl = CFRunLoopGetCurrent();
 
@@ -409,7 +495,7 @@ void fsm_listen__loop(struct fsmonitor_daemon_state *state)
 
 	switch (data->shutdown_style) {
 	case FORCE_ERROR_STOP:
-		state->error_code = -1;
+		state->listen_error_code = -1;
 		/* fall thru */
 	case FORCE_SHUTDOWN:
 		ipc_server_stop_async(state->ipc_server_data);
@@ -421,7 +507,7 @@ void fsm_listen__loop(struct fsmonitor_daemon_state *state)
 	return;
 
 force_error_stop_without_loop:
-	state->error_code = -1;
+	state->listen_error_code = -1;
 	ipc_server_stop_async(state->ipc_server_data);
 	return;
 }