ibus: the text before the cursor, and the runes to take back

RequireSurroundingText asks the client to send its text; it arrives
through SetSurroundingText as an IBusText and a cursor counted in
runes, and DeleteSurroundingText asks for runes back before the commit
that replaces them.  The official libibus client now proves the whole
turn: 한자 typed, the Hanja key, Enter, and 漢字 arrives with the 한
taken away.

A client that has set EffectivePostProcessKeyEvent is never asked for
its text.  It reads the key's commits back after ProcessKeyEvent
returns, and a DeleteSurroundingText signal is not one of the things
that reply can carry, so the deletion would land after the text it was
meant to make room for and eat the wrong runes.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

tests/ibus_client_smoke.c

@@ -30,6 +30,12 @@ struct Log
 	int	rcommit;
 	int	rdone;
 	int	flushed;
+	int	hanja;
+	int	required;
+	int	deleted;
+	int	delbefore;
+	int	delcount;
+	int	converted;
 };
 
 static void
@@ -142,6 +148,17 @@ commit(IBusInputContext *ctx, IBusText *text, void *arg)
 	log->commit++;
 	s = ibus_text_get_text(text);
 	attrs = ibus_text_get_attributes(text);
+	if(log->hanja){
+		/* The word converted, with the client\'s own syllable taken back. */
+		if(strcmp(s, "漢字") == 0 && log->deleted && log->delbefore == -1 &&
+		   log->delcount == 1)
+			log->converted = 1;
+		else
+			log->invalid = 1;
+		if(log->loop != NULL && log->waiting != NULL && *log->waiting)
+			g_main_loop_quit(log->loop);
+		return;
+	}
 	if(log->repeat == 3){
 		/* Focus loss hands the pending syllable back as a commit. */
 		if(strcmp(s, "ㅋ") == 0)
@@ -184,6 +201,32 @@ commit(IBusInputContext *ctx, IBusText *text, void *arg)
 		g_main_loop_quit(log->loop);
 }
 
+static void
+required(IBusInputContext *ctx, void *arg)
+{
+	Log *log;
+
+	(void)ctx;
+	log = arg;
+	log->required = 1;
+	if(log->loop != NULL && log->waiting != NULL && *log->waiting)
+		g_main_loop_quit(log->loop);
+}
+
+static void
+deleted(IBusInputContext *ctx, gint offset, guint n, void *arg)
+{
+	Log *log;
+
+	(void)ctx;
+	log = arg;
+	log->deleted = 1;
+	log->delbefore = offset;
+	log->delcount = n;
+	if(log->loop != NULL && log->waiting != NULL && *log->waiting)
+		g_main_loop_quit(log->loop);
+}
+
 static gboolean
 timeout(void *arg)
 {
@@ -214,7 +257,8 @@ int
 main(int argc, char **argv)
 {
 	IBusBus *bus;
-	IBusInputContext *a, *b;
+	IBusInputContext *a, *b, *c;
+	IBusText *around;
 	Log log;
 	int ok;
 
@@ -229,7 +273,7 @@ main(int argc, char **argv)
 		return 1;
 	}
 	memset(&log, 0, sizeof log);
-	b = NULL;
+	b = c = NULL;
 	ibus_init();
 	bus = ibus_bus_new();
 	if(bus == NULL || !ibus_bus_is_connected(bus)){
@@ -286,20 +330,55 @@ main(int argc, char **argv)
 	log.repeat = 3;
 	ibus_input_context_focus_out(a);
 	ok = ok && waitflag(&log, &log.flushed);
-	if(log.legacy == 0 || log.modern != 0 || log.commit != 4 ||
-	   log.invalid || !log.done || !log.atext || !log.aclear ||
-	   !log.retook || log.clearctx != a || !log.rdone)
+	/*
+	 * A word is committed a syllable at a time, so the Hanja key must
+	 * reach into what the client already holds and ask for it back.
+	 */
+	c = ibus_bus_create_input_context(bus, "strans-libibus-smoke-c");
+	if(c == NULL)
 		ok = 0;
+	else{
+		g_signal_connect(c, "commit-text", G_CALLBACK(commit), &log);
+		g_signal_connect(c, "require-surrounding-text",
+			G_CALLBACK(required), &log);
+		g_signal_connect(c, "delete-surrounding-text",
+			G_CALLBACK(deleted), &log);
+		log.repeat = 0;
+		ibus_input_context_set_capabilities(c,
+			IBUS_CAP_PREEDIT_TEXT|IBUS_CAP_SURROUNDING_TEXT);
+		ibus_input_context_focus_in(c);
+		ok = ok && waitflag(&log, &log.required);
+		around = ibus_text_new_from_string("저는 한");
+		ibus_input_context_set_surrounding_text(c, around, 4, 4);
+		log.hanja = 1;
+		ok = ok && ibus_input_context_process_key_event(c, 's', 0,
+			IBUS_CONTROL_MASK) &&
+			ibus_input_context_process_key_event(c, 'w', 0, 0) &&
+			ibus_input_context_process_key_event(c, 'k', 0, 0) &&
+			ibus_input_context_process_key_event(c, 'h', 0,
+			IBUS_CONTROL_MASK) &&
+			ibus_input_context_process_key_event(c, IBUS_KEY_Return,
+			0, 0) && waitflag(&log, &log.converted);
+		log.hanja = 0;
+	}
+
+	if(log.legacy == 0 || log.modern != 0 || log.commit != 5 ||
+	   log.invalid || !log.done || !log.atext || !log.aclear ||
+	   !log.retook || log.clearctx != a || !log.rdone || !log.converted)
+		ok = 0;
+	if(c != NULL)
+		g_object_unref(c);
 	if(b != NULL)
 		g_object_unref(b);
 	g_object_unref(a);
 	g_object_unref(bus);
 	if(!ok){
 		fprintf(stderr,
-			"ibus_client_smoke: legacy=%d modern=%d commit=%d invalid=%d preedit=%d committed=%d transfer-text=%d a-clear=%d retook=%d repeat=%s flushed=%d\n",
+			"ibus_client_smoke: legacy=%d modern=%d commit=%d invalid=%d preedit=%d committed=%d transfer-text=%d a-clear=%d retook=%d repeat=%s flushed=%d required=%d deleted=%d,%d converted=%d\n",
 			log.legacy, log.modern, log.commit, log.invalid,
 			log.sawpreedit, log.sawcommit, log.atext, log.aclear,
-			log.retook, log.revent, log.flushed);
+			log.retook, log.revent, log.flushed, log.required,
+			log.delbefore, log.delcount, log.converted);
 		return 1;
 	}
 	printf("official libibus client preedit, commit, owner clear, take-back and focus-out hand-back: ok\n");

tests/ibus_live_test.c

@@ -129,6 +129,7 @@ runcontract(char *address)
 		"SetCapabilities",
 		"SetCursorLocation",
 		"SetCursorLocationRelative",
+		"SetSurroundingText",
 	};
 	DBusConnection *conn;
 	char path[96];