error reading file created with Excel 2004 for Mac

```
Attempting to import the attached Test.xls file will result in

Notice: Undefined property: rootentry in excel_reader2.php on line 232
Notice: Undefined index: in excel_reader2.php on line 232
Notice: Undefined index: in excel_reader2.php on line 195
[last error repeats infinitely]

Attached patch.diff appears to resolve the problem.

For reference this is excel_reader2.php Version 2.21 on a G5 PowerMac with OS X
10.4.11 and PHP
4.4.9 (cli) using Excel 2004 for Mac 11.5.4
```

Original issue reported on code.google.com by `mwcre...@gmail.com` on 29 May 2009 at 6:22

Attachments:
- [Test.xls](https://storage.googleapis.com/google-code-attachments/php-excel-reader/issue-25/comment-0/Test.xls)
- [patch.diff](https://storage.googleapis.com/google-code-attachments/php-excel-reader/issue-25/comment-0/patch.diff)

Start with excel_reader2.php around lines 195 and 232, then compare the attached patch.diff and reproduce the problem with Test.xls. Done means importing the Excel 2004 file no longer emits the reported notices or repeats the final error indefinitely.

Written by the indexing model from the issue text.