Hi,
It was requested in the mailing list, twice IIRC, for double-clicking into Compiler or Messages tab to not only open the file and seek into it, but also focus the editor window. That makes sense, IMHO, since pressing Space opens and seeks, while Enter opens, seeks and focuses. It's a small patch, and I think it also improves the code a bit - using a gboolean looks better to me than passing a fake key 0 and constantly checking for enter-or-return.
Seeking into the file 3 times (release, 2button press, release) is not very good, but the subsequent seeks are quick. At least I'm not able to click so fast as to cause any delay.