NSSpellServer tearing my hair out no more! (fixed in 10.5.7)

13 Oct 2008

I just received confirmation mail from Apple‘s technician regarding this bug and 10.5.7. Thank you! It took them a while to nail it down, but finally we can change spell checker language w/o restarting Mail or Safari.

A story with happy ending

Since a while I am a happy Mac OS X user, would be happiest one, if only I could write my mails easily.

Even I find myself often talk too much I am neither a perfect speaker nor writer. So something commonly called “spell checker” is an invaluable tool in my daily work, especially when sending bunch mails per day. Short after my transition to Mac I was very excited finding out that spell checking is built into the system. Unfortunately as a spelling mistake prone Pole speaking usually English at work and Polish privately I realized that having no Polish spell checker makes my doom.

Mac Spell Checker

cocoAspell goes first

In late 2007 browsing trough various forums I discovered cocoAspell, an extra spell checker service for OSX using aspell dictionaries. It was working pretty well, if only it was not crashing. cocoaSpell was not also fastest software I ever seen. Additionally I noticed everything I tried I was unable to perform successful switch to other language while already working in Mail.app, so it had to be restarted after every switch. That was terrible annoyance.

Anyway I was blaming cocoAspell, for not being updated for a long while.

Meeting CheckSpell

In early 2008 the very first version of CheckSpell was released, with all its glory going to Marcin Dalecki (the author) for addressing all the drawbacks of cocaSpell such as performance, stability and flexibility and all the joy to ex-cocoaSpell users. After the first release I was working a bit with Marcin to fix some minor glitches of CheckSpell. Hitting 1.3 we have realized that Mail.app (and other apps) language switching problem is something that lays in the system framework and we cannot do anything about without Apple‘s help. Soon the others confirmed the problem.

Being a patient reporter

I rushed to Apple’s Mac OS X feedback page, filling the report. Bang, .. “thank you for your report”. Great! What now? Argh, what I should expect. I was looking on 10.5.2, 10.5.3, 10.5.4 passing by. And the bug was still there.

Being not discouraged, I kept trying to nail down the problem. It led me to Foundation.framework of Mac OS X stubbornly calling wrong spell server.

Let me introduce you the bug

  1. AppleSpell.service NSSpellServer is registered with registerLanguage:byVendor: for “en“, “fr” … etc. languages and “Apple” vendor.

  2. CheckSpell.service NSSpellServer is registered for exclusively other languages as “pl“, “cs“, “lt“, “lv“, “sk” … with “Apple” vendor (“Apple” is used here to avoid having vendor name in the list, however I checked for the bug using different vendor name “Check“, and it occurs as well).

So it often happens that Foundation calls CheckSpell.service for “en” and vice-versa AppleSpell.service for “pl“! This happens by instance in Mail.app, when I first use English spell checking via AppleSpell.service, and switch to Polish (pl) via CheckSpell.service for my next mail, Foundation (NSSpellChecker) is getting crazy, and asking AppleSpell for “pl“, which results in totally wrong (empty) response. In order to get proper “pl” via CheckSpell.service I need to restart Mail.app, but then when I want to switch to English, once again I need to restart.

This problem hits all users using some extra spell checkers also CocoaSpell, so all eastern Europe, and all people using multiple languages at Mail.app.

But most important thing is that this problem is not related explicitly to Mail.app, which is just a reference. All applications using Foundation‘s spelling interface, such as Safari are affected. So yes, you need to restart your Safari closing all open windows and tabs if you want to switch spelling language when you type your blog or forum post.

How to reproduce it

  1. Download and install CheckSpell.

    The installer will create /Library/Services/CheckSpell.service which is spell server based on NSSpellServer Cocoa API. Once it is installed you should see additional languages such as Polski or Cestina. Let’s try reproduce the bug with Polish<->English switching.

  2. Try to open Mail.app and write new mail as below:

     Here below is some Polish sentence. Tutaj u góry jest tekst po

Expected results

1st line should be valid only in English (AppleSpell) spelling language set, 2nd should be valid only in Polish (CheckSpell).

Actual results

Unfortunately when I start writing mail with English spelling, switching to Polish doesn’t really make 2nd line valid, I get absolutely no response from Polish spell checker (probably AppleSpell is getting called with “pl” instead of CheckSpell)

Once the mail is saved and Mail.app restarted, it starts fine with Polish, until the switch back to English. Then CheckSpell is complaining that it is getting called with “en” language which it wasn’t registered for (AppleSpell should be called).

Note that..

When you do: killall AppleSpell CheckSpell prior running Mail.app, switching spelling languages works somehow fine! So the problem appears when AppleSpell & CheckSpell service processes are already running in the system. So the problem may not appear 1st time when you run Mail.app after installation of CheckSpell, please rerun it once both spelling service processes are running.

So the diagnosis is that once single application using Foundation.framework contacts the NSSpellServer that is already running, it will always use THIS one regardless of selected language and other NSSpellServer that may be proper.

Additionally all NSTextView based GUIs such as Mail.app miss revalidation. Every time you change the language in Spelling & Grammar window and you got Check spelling as you type ON the spelling is not revalidated with current language, you need to click Next many many times, or scroll your cursor trough whole document in order to make the spelling underline incorrect words in current language. This is also the case when you open the saved mail in Mail.app, incorrect words are not underlined on open.

Catching up bit closer with Apple

I have subscribed to cocoa-dev mailing list and sent there the report. What was my (positive) surprise when I received a response from Apple‘s employee asking for some extra details and claiming they will have a look at this. Woah, I thought, you rock dudes!

After I send the guy few extra lines about my configuration etc. I started looking towards the response and hopefully the FIX itself. None of them arrived. I have resent some mails asking for the contact, no reply. I have asked for feedback again on cocoa-dev, no reply. Even I saw the guy posting in other threads on the list.

Finally I filled bug 6206237 at bugreport.apple.com as some list member (but not an Apple’s employee) advised me.

Trying to believe I did something wrong

Apple, you should respond “Bugger off!” at the very beginning – to all the bug reports I have sent, to all OSX users that use custom spell checker. It is 10.5.5 right now and we still need to live with this bug.

All this makes me understand that the Apple’s way is to stay quiet as the grave, if there is any problem regarding their products. But there is no conclusion there, all I can say I feel the pity that all my reports gone into the drain and OSX cannot be pushed closer to the perfection (even it could), making myself and many my fellow countrymen happier.

I encourage everybody to post comments below about their experiences with this problem. Hope someday this will hit the eye of Apple’s management.


After having a sleep with the problem in my head, I tend to believe only way is to add English, French, etc. spelling checking into CheckSpell and manually disable AppleSpell.service. This should make the trick, even it is quite bad idea to touch /System/Library/Services.

~~You can help~~

~~If you have ADC account please fill a bug report at bugreport.apple.com and reference Problem ID 6206237. Unfortunately Apple does not let you see other problems than just yours.~~

Posted in Mac