What does the Eclipse console scroll lock button do?

Im pretty sure i know what its supposed to do, but enabling/disabling makes absolutely no difference in my eclipse setup (3.6).

New output still scrolls the console even if i am not positioned to show the last sc开发者_高级运维reen full.

Am I missing anything?

It looks like bug 316981:

We have found an understandable but unexpected issue with the scroll lock feature, by exposing it via SSH to the following shell script:

#!/bin/sh
X=1
while true ; do
  X=`expr $X + 1`
  echo "Hello $X"
done

Running this script, the "scroll lock" feature does not work.
The problem with the test case is that new lines are printed so quickly, that the Terminal Widget's buffer runs over.

Fix:

Window > Preferences > Terminal : 
Set "Terminal Buffer" to 100000 lines

Now, scroll lock works as expected even with this case (until 100000 lines are reached).