bitcoin/bitcoin — pull request #2741 by theuni (2013-06-05 03:58:58+00:00)
Title: osx: fix bitcoin-qt startup crash when clicking dock icon

Fixes a regression from Crash probably introduced by 4d17a1b0.
Initialize the window to NULL and verify it before use.

Triggered in this case by running ./bitcoin-qt from a shell, and clicking on the icon before the window comes up.