From 45629480a3673e79569468d52ee28dbefce21b7f Mon Sep 17 00:00:00 2001
From: xiepengfei <xiepengfei@uniontech.com>
Date: Fri, 18 Sep 2026 22:43:57 +0800
Subject: [PATCH] fix: guard null pointer in updateViewModeActions
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1. Root cause: m_actLivePreview is initialized to nullptr and only
   assigned in initRightClickedMenu(), but updateViewModeActions() can
   be called via signal/slot before initialization completes
2. Fix: add null check before calling setEnabled on m_actLivePreview,
   consistent with the existing null-safe pattern on the preceding line
3. Impact: prevents null pointer dereference crash when switching view
   modes before right-click menu initialization

Influence:
1. Test switching view modes before opening right-click menu
2. Test markdown file open and view mode toggle
3. Verify no regression on normal view mode switching

fix: 修复updateViewModeActions空指针解引用问题

1. 根因：m_actLivePreview初始化为nullptr，仅在initRightClickedMenu()
   中赋值，但updateViewModeActions()可通过signal/slot在初始化前被调用
2. 方案：在调用m_actLivePreview->setEnabled前添加空指针检查，与同
   函数已有的空安全模式保持一致
3. 影响：防止右键菜单初始化前切换视图模式导致的空指针崩溃

Influence:
1. 测试右键菜单初始化前切换视图模式
2. 测试Markdown文件打开及视图模式切换
3. 验证正常视图模式切换无回归

PMS: BUG-186
---
 src/editor/dtextedit.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/editor/dtextedit.cpp b/src/editor/dtextedit.cpp
index 545865df..5e2e2e36 100644
--- a/src/editor/dtextedit.cpp
+++ b/src/editor/dtextedit.cpp
@@ -5046,7 +5046,8 @@ void TextEdit::updateViewModeActions(ViewMode mode, bool isMarkdown)
     if (action && !action->isChecked())
         action->setChecked(true);
     // 置灰规则（§4.4）：非 md 文件仅「实时预览」置灰，编辑/查看始终可用
-    m_actLivePreview->setEnabled(isMarkdown);
+    if (m_actLivePreview)
+        m_actLivePreview->setEnabled(isMarkdown);
 }
 
 void TextEdit::SendtoggleReadmessage()