bitcoin-qt.exe gitian win32: missing icon and runs blank terminal window #3499

Something changed with bitcoin-qt.exe built by gitian win32. The .exe is missing the Bitcoin icon and launching it opens a blank terminal window before the splash screen appears.

Built at 13e99e463d4aa0bd2b2892010ca8c7007c40c242

As for the console window: we need to add an -mwindows to the linking step of the bitcoin-qt.exe (but NOT bitcoind.exe or bitcoin-cli.exe, as they need a console).

For the icon I think we need to compile and link in the win32 resources file src/qt/res/bitcoin-qt.rc. @theuni Do you have a suggestion on how to do this with autotools?

AFAIK there are res files for bitcoind.exe and bitcoin-cli.exe already... The lines that are responsible for adding an icon to an executable file are (from: bitcoin-qt-res.rc)

<pre> IDI_ICON1 ICON DISCARDABLE "icons/bitcoin.ico" IDI_ICON2 ICON DISCARDABLE "icons/bitcoin_testnet.ico" </pre>

The problem is that they aren't used.

AFAIK @theuni added a patch, that they should be used some time ago? Anyway, the only file that adds an icon, is the .rc file for Bitcoin Core, the .rc files for bitcoind.exe and bitcoin-cli.exe are missing the mentioned entries from above.

Ok, so bitcoind.exe and bitcoin-cli.exe are fine?

But the gitian-built bitcoin-qt.exe however has no icon and opens a console window. Is this the same for your local builds or a gitian problem?

Must be a Gitian problem, as I have an icon and also no console window.

@Diapolo can you confirm with self-built/gitian .exe's exactly what the issues are here? I'm happy to fix, but I'm in the dark without Windows.

I don't Gitian build and (sorry) also didn't yet test the now merged Qt5 autotools patch (great work btw.). My local builds currently rely on an older bitcoin-qt.pro files, to which I added needed changes to catch up with current master. Anyway, my bitcoin-qt.exe file has an application icon (the file itself, when viewed in Windows Explorer) and also doesn't open a blank terminal window (this can be cause by a missing -mwindows as @laanwj suggests or perhaps we have some debugging stuff enabled? dunno).

Note that the blank terminal window is not always blank -- it's the output (I don't know if it's stdout, stderr, or something else). I have -tor set in my config file, and the terminal window that opens with the GUI shows a message about the option being renamed to -onion in a future release.

Indeed, the console window is Windows standard output, anything that's written to standard output ends up there.

@theuni Do you have any recommendations on how to make sure that -mwindows is passed when linking bitcoin-qt.exe? I know how to do it, but maybe you have a preference as to how.

If you want to distinguish between the two subsystem modes without Windows you can use the following commands:

Good:

$ objdump -x bitcoin-0.8.99-win32-setup.exe | grep -i "^Subsystem"
Subsystem               00000002        (Windows GUI)
$ objdump -x bitcoind.exe |grep -i "^Subsystem"
Subsystem               00000003        (Windows CUI)
$ objdump -x bitcoin-cli.exe |grep -i "^Subsystem"
Subsystem               00000003        (Windows CUI)

Wrong, should be GUI:

$ objdump -x bitcoin-qt.exe |grep -i "^Subsystem"
Subsystem               00000003        (Windows CUI)

@laanwj Need to check -mwindows in configure before passing it along (AX_CHECK_LINK_FLAG), then pass it along in a GUI_FLAGS or so. I'll push up a patch in a few hours when I can build/test.