TYPO3 Core

Yes, it is.
I found a similar bug report at http://lists.typo3.org/pipermail/typo3-project-rte/2012-January/002322.html

Maybe this could help.

Are you sure that fwrite is capable of writing utf-8 without encoding?

Gerhard Rupp wrote:

Are you sure that fwrite is capable of writing utf-8 without encoding?

Well, the word is correctly written in the temp file.

Gerhard Rupp wrote:

Yes, it is.
I found a similar bug report at http://lists.typo3.org/pipermail/typo3-project-rte/2012-January/002322.html

Maybe this could help.

This will not work in the general case.

In think that the problem is that Aspell expects the word to be in the same charset as the dictionary being used. I am trying to find how to know in what charset the dictionary is encoded.

This is now fixed in master.

I think this is an Aspell issue. Here is the work around:
- before submitting additions to the personal word list or to the personal replacement pairs, access the main dictionary currently in use and retrieve the encoding specified in the file;
- convert the additions to the personal word list or to the personal replacement pairs to the encoding of the main dictionary.

The above will work only if the personal dictionaries are utf-8-encoded. Therefore, before submitting any request to Aspell, read the personal dictionary files and ensure that the encoding option is set to utf-8. If not, set the option to utf-8 and update the files.

Now need to backport to the stable releases.

Please test this change on TYPO3 4.5: http://review.typo3.org/12680

I can confirm that this patch works on a windows server on TYPO3 4.5.17.

This patch seems not to be included in TYPO3 4.5.18.

Patch set 1 for branch TYPO3_4-7 has been pushed to the review server.
It is available at http://review.typo3.org/15467