Putty prematurely terminates when clicking the Connect button while running in a Wayland session

[林博仁(Buo-ren Lin)]

## Bug reproducing instructions

1. Ensure you're in a Wayland session.
2. Launch a text terminal emulator.
3. Run the `putty` command to launch Putty.
4. In the "Session > Specify the destination you want to connect to" panel, type any character into the "Host Name (or IP address)" field, then click the "Open" button at the bottom.

## Current behavior

The application window will close with the "1" exit status code. In the text terminal emulator, the following error message is printed:

```text
PuTTY: unable to load font "server:fixed"
```

If you launch Putty using the following command(forcing it to be run on XWayland), the problem will no longer be reproduced:

```sh
env GDK_BACKEND=x11 putty
```

This bug has already been fixed in the Fedora packaging: <https://src.fedoraproject.org/rpms/putty/c/385449d>, we probably should port their patch here.

## Expected behavior

No crashes.

## Additional information

### OS release

Ubuntu 24.04

### Processor architecture

AMD64

### Desktop environment

KDE Plasma

### Putty version

```text
PuTTY: Release 0.81
Build platform: 64-bit Unix (GTK + X11)
Compiler: gcc 13.2.0
Compiled against GTK version 3.24.41
Source commit: a8601a72a918dfc2a8e8536a77139d7f37700044
```

### `putty` package version

0.81-1

### Locale settings

```sh
LANG=zh_TW.UTF-8
LANGUAGE=zh_TW:zh_CN:en
LC_CTYPE="zh_TW.UTF-8"
LC_NUMERIC=zh_TW.UTF-8
LC_TIME=zh_TW.UTF-8
LC_COLLATE="zh_TW.UTF-8"
LC_MONETARY=zh_TW.UTF-8
LC_MESSAGES="zh_TW.UTF-8"
LC_PAPER=zh_TW.UTF-8
LC_NAME=zh_TW.UTF-8
LC_ADDRESS=zh_TW.UTF-8
LC_TELEPHONE=zh_TW.UTF-8
LC_MEASUREMENT=zh_TW.UTF-8
LC_IDENTIFICATION=zh_TW.UTF-8
LC_ALL=
```

ProblemType: Bug
DistroRelease: Ubuntu 24.04
Package: putty 0.81-1
ProcVersionSignature: Ubuntu 6.11.0-21.21~24.04.1-generic 6.11.11
Uname: Linux 6.11.0-21-generic x86_64
ApportVersion: 2.28.1-0ubuntu3.5
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: KDE
Date: Sun Apr 13 19:51:55 2025
InstallationDate: Installed on 2025-02-04 (68 days ago)
InstallationMedia: Ubuntu 24.04.1 LTS "Noble Numbat" - Release amd64 (20240827.1)
SourcePackage: putty
UpgradeStatus: No upgrade log present (probably fresh install)

[Jacob Nevins (0jacobnk-ulp)]

I believe this is fixed more thoroughly upstream as of version 0.83.
(relevant commits: on main:
https://git.tartarus.org/?p=simon/putty.git;a=commit;h=b088d77d580b8f7e01482aa184db6cf3b46d74eb
https://git.tartarus.org/?p=simon/putty.git;a=commit;h=7f4cccde2ae53c083ababaaea19be4a9c45b7091
https://git.tartarus.org/?p=simon/putty.git;a=commit;h=6155365076c47a852d9d4e3e0a437787ac747d28
all cherry-picked on 0.83 release branch as
https://git.tartarus.org/?p=simon/putty.git;a=commit;h=293be04298e91b0b0a86230df60e72346da9987f )

[林博仁(Buo-ren Lin) (brlin)]

@Jacob Nevins

Great discovery, I wonder whether the upstream patch is more SRU-favorable as it comprises more lines of code changes, though.

[Jacob Nevins (0jacobnk-ulp)]

The Fedora change (build with -DNOT_X_WINDOWS) is also somewhat intrusive, since it removes native X11 support from the build entirely.
One consequence would be that anyone running PuTTY with an X11 server who's configured it to use a server-side font would be unable to launch their sessions (and use their chosen font) at all.