<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/81536>81536</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            lldb crashes when using tab completion.
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            lldb
      </td>
    </tr>

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

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

<pre>
    lldb version: trunk.

a.cpp
```
class B {
  int x;
};
class A {
  B t;
  int t2;
};

int main(int argc, char* argv[]) {
 A a;
  return 0;
}
```

command:
`clang++ -g a.cpp && lldb a.out -o "b a.cpp:11" -o "r"`

Enter `a.t.` and use tab completion causes lldb to crash:
```
(lldb) p a.t.terminate called after throwing an instance of 'std::out_of_range'
  what():  basic_string::substr: __pos (which is 4) > this->size() (which is 3)
LLDB diagnostics will be written to /tmp/diagnostics-eaf5b2
Please include the directory content when filing a bug report
[1]    2833408 IOT instruction  lldb a.out -o "b a.cpp:11" -o "r"
```
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJyUVE2r6zYQ_TWTzRAjjz_vwouk9wYKD9pFodDNRZYntlpFSqXxTV9_fbGd3iblbR4YWR9Hc2aODqNTsqNn7qA6QvW607NMIXa_8Z-z9r_Ouz4MXzvnhh4_OCYbPBQHlDj7PzJQr6AO26gzc73eN2p1_9alcTolPCI0x20D0XrBv6C4r6F5_Zxv4MMj-IjyebxdFfrm3W1cABdtPVC7THUcDdAPaCYdgQ7L-mOrFOjlgeaA-oElsszRo3ri-VZx96zD5aL9AMXhE2Sc9iPQEeiI-xFXeRCoBqpxVVNnYRbcBwSifjuH4pDnQHTfjUD0P6I3LxwRaqUzyaBWqP2Ac2IU3aMJl6tjscGj0XPitBFJQBN1mh6zeyqB2gW3yHHFJa5wvFivhdFo53hAfV5YZYrhZv2I2qP1SbQ3jOGMQE2StfbiEGZ5D-f3qP3IQM2_ct4mLUAt0MtiHux1suY9SbR-3O6luU8Sl8P392tICNTeJmsmtAnL9aGKN5TJpj0Ub8n-zVu0J1yxhF8Jv3x5PeJg9ehDEmsS3qxz2DPeohVhv0gCdJLLFej0gNuzPlc9bUF-dqwTo_XGzQOjTIyDjWwkxK9oghf2greJPZ6tW2XBfh4x8jVEuStbHXOoXhERqS2KUrX440-_rOLF2awP9V1eeH693dAVw0vxonfc5Y1qmoZa1eymrsiJ85da1YMqVVGez1yVLZ-Hmvo-N6re2Y4UlYpyopyUarLmXFYDV23ZV83Q1Ayl4ou2LnPu45KFOO5sSjN3bV4V9c7pnl1a-wXRZh1aOkfsFvi-n8cEpXI2SfovgFhxvPWR1Y2cNvHmtGj3bN9sN0fXTSLXtNiDTkCn0co095kJF6DTEvX-219j-J2NAJ3WHBPQaU3znwAAAP__PINrUw">