Surprises in eclipse 3.3: double click instead of single click

Since some time, the 3.3 patch editor (Team->Apply patch...) does not work for me anymore. Well, I was using patched milestones (we had some enhancements for the patch editor in our product). So, I was not surprised that it did not 100% work. What went wrong? If I select a file to patch, nothing is shown in the compare area below:

Since the problem remained even with an unpatched 3.3m7, I filed bug 186481 and after some discussions, it turned out that I have to double click instead of single click to select the patch. That was not obvious to me! In 3.2 a single click was enough! After double clicking the patch it looks like this:

Now I see exactly what I expected! But why double click? Well, because calculating the diff is expensive and doing that by simply selecting a file may not be a good idea... Another reason is that there's now a context menu on the items in the "Patch Contents" pane and you don't want to do the expensive calculation of the diff just to get to the context menu. Therefore, the paradigm changed from master-detail to open semantics.

But this is not without drawbacks! First of all, I'm sure I'm not the only one stumbling over this problem. Actually the semantics has changed in other compare related views too. If you set Preferences...->General->Single Click, you get the old master-detail behaviour.

Second drawback, is that the selection and what you see easily may get out of sync. Look at this screenshot:

What happened? I have selected (not double clicked) the plugin.properties file but the difference of a java file is shown. The bad thing is there is no indication which java files is shown here! Unfortunately it's too late in the game to change this (see bug 186481 for further details)...

Take-home message: Report bugs early enough....