Tighten SSH option passthrough

Previously, options without values (e.g. `-t`) would be passed as:
('-t', '')

When passed through to the shell, this became the following:
-t ''

This is unfortunately not the same as intended:
-t

Additionally, previously we indiscriminately appended `--` to the
`az ssh vm` command, even if it was not needed. Now, we only do that
when options or arguments are specified.

README.md

@@ -23,7 +23,8 @@ https://github.com/Azure/azure-cli-extensions/issues/7285
 - An Azure VM with the `AADSSHLoginForLinux` VM extension installed.
 - An Entra account with the `Virtual Machine Administrator Login` or
   `Virtual Machine User Login` role configured for the VM.
-- Linux or WSL
+- Linux or WSL (Windows is not supported due to
+  <https://github.com/PowerShell/PowerShell/issues/24585>).
 
 ## Install from PyPI
 

az_ssh_wrapper.py

@@ -67,8 +67,16 @@ def main():
     # Work around quoting issue on Windows (still works on Linux)
     az_path = f'"{az_path}"'
 
-    ssh_opts = [" ".join(opt) for opt in filter(opt_filter, opts)]
-    exec_args = [az_path, "ssh", "vm", "--ip", destination, "--", *ssh_opts, *args]
+    ssh_opts = []
+    for opt in filter(opt_filter, opts):
+        # Only keep truthy options. e.g.
+        # ('-t', '') --> ('t',)
+        # (Yes, this is important.)
+        ssh_opts += filter(lambda o: o, opt)
+
+    exec_args = [az_path, "ssh", "vm", "--ip", destination]
+    if ssh_opts or args:
+        exec_args.extend(["--", *ssh_opts, *args])
 
     os.execvp("az", exec_args)
 

pyproject.toml

@@ -3,7 +3,7 @@ name = "az-ssh-wrapper"
 authors = [
   {name = "David Wales", email = "david.wales@swsphn.com.au"}
 ]
-version = "1.0.2"
+version = "1.0.3"
 description = "SSH Wrapper for Azure CLI's `az ssh` command"
 readme = "README.md"
 license = {file = "LICENSE"}