Fix variable shadowing in insertTag causing incorrect tag parameter checks

[Copilot]

The insertTag method had a local variable tag that shadowed the method parameter tag, causing the condition if (tag === 'del') at line 152 to check against a formatted HTML tag string (e.g., '<del>') instead of the parameter value ('del'). This made the condition unreachable.

Changes

• Renamed local variable from tag to htmlTag to eliminate shadowing
• Updated reference to push htmlTag to the specialTagDiffStack

// Before: local variable shadows parameter
let tag = '<' + matchedTag?.[0].replace(/(<|>| )/g, '') + '>'
this.specialTagDiffStack.push(tag)
if (tag === 'del') { /* never true */ }

// After: distinct names
let htmlTag = '<' + matchedTag?.[0].replace(/(<|>| )/g, '') + '>'
this.specialTagDiffStack.push(htmlTag)
if (tag === 'del') { /* now checks parameter correctly */ }

The condition at line 167 was unaffected as the local variable was already out of scope.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>[insertTag方法中存在变量名混淆导致的逻辑错误]</issue_title>
<issue_description># Issue: [insertTag方法中存在变量名混淆导致的逻辑错误]

问题描述

在Diff.ts文件的insertTag方法中，存在变量名混淆导致的逻辑错误。方法参数tag与局部变量tag使用了相同的名称，导致在某些条件下判断的不是预期的变量。

问题代码位置

insertTag(tag: string, cssClass: string, words: string[]) {
  // ...
  if (specialCaseOpeningTagRegex.test(words[0])) {
    let matchedTag = words[0].match(specialCaseOpeningTagRegex)
    let tag = '<' + matchedTag?.[0].replace(/(<|>| )/g, '') + '>'  // 局部变量tag与参数tag同名
    this.specialTagDiffStack.push(tag)
    specialCaseTagInjection = '<ins class="mod">'
    if (tag === 'del') {  // 这里判断的是局部变量tag，但格式是'<del>'，所以永远不会是'del'
      words.shift()
      while (words.length > 0 && specialCaseOpeningTagRegex.test(words[0])) {
        words.shift()
      }
    }
  } else if (specialCaseClosingTags.has(words[0])) {
    // ...
    if (tag === 'del') {  // 这里判断的是方法参数tag ('del'字符串)
      words.shift()
      while (words.length > 0 && specialCaseClosingTags.has(words[0])) {
        words.shift()
      }
    }
  }
  // ...
}

建议修复

为了避免变量名混淆，应将局部变量重命名为更具有描述性的名称：

insertTag(tag: string, cssClass: string, words: string[]) {
  // ...
  if (specialCaseOpeningTagRegex.test(words[0])) {
    let matchedTag = words[0].match(specialCaseOpeningTagRegex)
    let htmlTag = '<' + matchedTag?.[0].replace(/(<|>| )/g, '') + '>'  // 重新定义变量名称
    this.specialTagDiffStack.push(htmlTag)
    // ...
    }
}
```</issue_description>

## Comments on the Issue (you are @copilot in this section)

<comments>
</comments>

• Fixes [insertTag方法中存在变量名混淆导致的逻辑错误] #1

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