<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/75035>75035</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            clang-format Leave option for AlignTrailingComments is broken
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            clang-format
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          ChristophStrehle
      </td>
    </tr>
</table>

<pre>
    looks like the Leave option for AlignTrailingComments is broken in clang-format 17.0.6 when using tabs for indentation.

When formatting the following code:
```
namespace mynamespace {
// My struct
struct MyStruct final {
        constexpr int NoError{0};               //!< Successfully
        constexpr int Error{1};         //!< Error
};
} // namespace mynamespace
```
with this command line:
`clang-format -style="{Language: Cpp, UseTab: Always, IndentWidth: 4, TabWidth: 4, AlignTrailingComments: {Kind: Leave}}"`
I get the following output after the first run:
```
namespace mynamespace {
 // My struct
struct MyStruct final {
        constexpr int NoError{0};  //!< Successfully
        constexpr int Error{1}; //!< Error
};
} // namespace mynamespace
```
That means that clang-format will change the indentation of the trailing comments by replacing the tabs with spaces.

Even worse then the trailing comments is that clang-format will insert a space in front of the comment `// My struct` in the first run. In a second run clang-format will insert a second space, then a third space, then a tab and then two spaces again. 
</pre>
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