Fixed the bug whereby PuTTYgen went into generation mode as soon as

it started up. The problem was that I was accepting _any_ event on
IDC_GENERATE to trigger this, not just the `clicked' event, and some
uninteresting event like `initialise' must have occurred. Quite why
this only showed up as a result of the config box revamp I can't
imagine.

[originally from svn r2972]

puttygen.c

@@ -1050,6 +1050,9 @@ static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
             }
 	    return 0;
 	  case IDC_GENERATE:
+            if (HIWORD(wParam) != BN_CLICKED &&
+                HIWORD(wParam) != BN_DOUBLECLICKED)
+		break;
 	    state =
 		(struct MainDlgState *) GetWindowLong(hwnd, GWL_USERDATA);
 	    if (!state->generation_thread_exists) {