Looks good to me on gpg4win-5.0.0-beta357 @ win10 for the following migrations (as stated in the description):

• gpg4win 4.3.1 -> gpg4win 5.0
• gpg4win 4.4.1 -> gpg4win 5.0

Pushed the changes in {gniibe/synch-spawn} branch.
It consists of three commits:

• rGb8b8afc5cf6f: build: Require libgpg-error 1.56 or newer.
• rG15b8bc7495db: w32: Synchronous spawning gpg-agent/dirmngr/keyboxd.
• rG6bd6826aa6ff: common:w32: Care about the NUL device for start_new_service.

There is a new --keyserver-option update-before-send which is enabled by default.

Done for gpg4win 5 and backported for VSD 3.4 (provided that the gpg4win-4-branch will be used for VSD 3.4).

Deselect email and select again (email gets decrypted again) attachments are back.

Several releases since the last commit and no specific bug reports. We can close this task.

Add gpd5x tag to ensure testing with Gpg4win.

Fixed with new GPGRT_PROCESS_STDIO_NUL flag.

Pushed the changes:

• Inheriting HANDLEs has been not working accurately
  • Before the fix, all HANDLEs were inherited
  • Only specified HANDLEs are inherited by: rE0b01950237ab: w32:spawn: Fix inheriting HANDLEs.
• HANDLEs by w32_open_null were leaked
  • fixed by: rEf28bf71b86ba: w32:spawn: Fix resource leaks for HANDLEs by w32_open_null.

T7723 fix by rE311fb769d1dd: w32:spawn: New flag GPGRT_PROCESS_STDIO_NUL.

Before implementing this feature, it's better to fix T7723: gpgrt:w32: Fix for inheriting stdin/stdout/stderr with "NUL", and do some clean up.

If we will fix gpgconf using GPGRT_PROCESS_IO_NUL, we will need to fix gpg-connect-agent to see if it's NUL or not.

Here is an experimental change to support the feature.

I'm testing the following patch with experimental change of libgpg-error.

Can't you just use file descriptors everywhere and use _get_osfhandle once you need a HANDLE. That is what I am used to seeing in Windows code in Gnulib (although I do not touch it much).

Regarding 64bit handles https://learn.microsoft.com/en-us/windows/win32/winprog64/interprocess-communication
tells us:

This seems to be a good opportunity to replace paperkey with a new tool to take advantage of the smaller ECC keys which allow us to re-generate most stuff.