From 051203b0814bc498e4e648cc7080b3d5eb203548 Mon Sep 17 00:00:00 2001
From: ShikiSuen <shikisuen@outlook.com>
Date: Tue, 22 Feb 2022 22:06:08 +0800
Subject: [PATCH] KeyHandler // Cancel the CandidateState when Builder is
 Empty.

---
 Source/Modules/ControllerModules/KeyHandler.mm | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Source/Modules/ControllerModules/KeyHandler.mm b/Source/Modules/ControllerModules/KeyHandler.mm
index 44cd1383..3007bd69 100644
--- a/Source/Modules/ControllerModules/KeyHandler.mm
+++ b/Source/Modules/ControllerModules/KeyHandler.mm
@@ -1000,6 +1000,12 @@ static NSString *const kGraphVizOutputfile = @"/tmp/vChewing-visualization.dot";
             [self clear];
             InputStateEmptyIgnoringPreviousState *empty = [[InputStateEmptyIgnoringPreviousState alloc] init];
             stateCallback(empty);
+        } else if ([self isBuilderEmpty]) {
+            // 如果此時發現當前組字緩衝區為真空的情況的話，就將當前的組字緩衝區析構處理、強制重設輸入狀態。
+            // 不然的話，一個本不該出現的真空組字緩衝區會使前後方向鍵與 BackSpace 鍵失靈。
+            [self clear];
+            InputStateEmptyIgnoringPreviousState *empty = [[InputStateEmptyIgnoringPreviousState alloc] init];
+            stateCallback(empty);
         } else {
             InputStateInputting *inputting = (InputStateInputting *)[self buildInputtingState];
             stateCallback(inputting);