Fix ssh kitten override parsing ignoring settings inherited from ssh.conf

Fixes #6639

docs/changelog.rst

@@ -43,6 +43,14 @@ The :doc:`ssh kitten <kittens/ssh>` is redesigned with powerful new features:
 Detailed list of changes
 -------------------------------------
 
+0.30.1 [future]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+- ssh kitten: Fix a regression in 0.28.0 that caused using ``--kitten`` to
+  override :file:`ssh.conf` not inheriting settings from :file:`ssh.conf`
+  (:iss:`6639`)
+
+
 0.30.0 [2023-09-18]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

docs/kittens/ssh.rst

@@ -82,10 +82,10 @@ Additionally, you can pass config options on the command line:
    kitty +kitten ssh --kitten interpreter=python servername
 
 The :code:`--kitten` argument can be specified multiple times, with directives
-from :file:`ssh.conf`. These are merged with :file:`ssh.conf` as if they were
-appended to the end of that file. They apply only to the host being SSHed to by
-this invocation, so any :opt:`hostname <kitten-ssh.hostname>` directives are
-ignored.
+from :file:`ssh.conf`. These override the final options used for the matched host, as if they
+had been appended to the end of the matching section for that host in
+:file:`ssh.conf`. They apply only to the host being SSHed to by this invocation,
+so any :opt:`hostname <kitten-ssh.hostname>` directives are ignored.
 
 .. warning::
 

kittens/ssh/config.go

@@ -391,9 +391,20 @@ func (self *ConfigSet) line_handler(key, val string) error {
 func load_config(hostname_to_match string, username_to_match string, overrides []string, paths ...string) (*Config, []config.ConfigLine, error) {
 	ans := &ConfigSet{all_configs: []*Config{NewConfig()}}
 	p := config.ConfigParser{LineHandler: ans.line_handler}
-	err := p.LoadConfig("ssh.conf", paths, overrides)
+	err := p.LoadConfig("ssh.conf", paths, nil)
 	if err != nil {
 		return nil, nil, err
 	}
-	return config_for_hostname(hostname_to_match, username_to_match, ans), p.BadLines(), nil
+	final_conf := config_for_hostname(hostname_to_match, username_to_match, ans)
+	bad_lines := p.BadLines()
+	if len(overrides) > 0 {
+		h := final_conf.Hostname
+		override_parser := config.ConfigParser{LineHandler: final_conf.Parse}
+		if err = override_parser.ParseOverrides(overrides...); err != nil {
+			return nil, nil, err
+		}
+		bad_lines = append(bad_lines, override_parser.BadLines()...)
+		final_conf.Hostname = h
+	}
+	return final_conf, bad_lines, nil
 }

kittens/ssh/config_test.go

@@ -24,11 +24,14 @@ func TestSSHConfigParsing(t *testing.T) {
 	hostname := "unmatched"
 	username := ""
 	conf := ""
+	overrides := []string{}
 	for_python := false
 	cf := filepath.Join(tdir, "ssh.conf")
 	rt := func(expected_env ...string) {
-		os.WriteFile(cf, []byte(conf), 0o600)
-		c, bad_lines, err := load_config(hostname, username, nil, cf)
+		if err := os.WriteFile(cf, []byte(conf), 0o600); err != nil {
+			t.Fatal(err)
+		}
+		c, bad_lines, err := load_config(hostname, username, overrides, cf)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -52,6 +55,10 @@ func TestSSHConfigParsing(t *testing.T) {
 	rt()
 	conf = "env a=b"
 	rt(`export 'a'="b"`)
+	conf = "env a=b"
+	overrides = []string{"env=c=d"}
+	rt(`export 'a'="b"`, `export 'c'="d"`)
+	overrides = nil
 
 	conf = "env a=\\"
 	rt(`export 'a'="\\"`)

kittens/ssh/main.go

@@ -115,9 +115,6 @@ func parse_kitten_args(found_extra_args []string, username, hostname_for_match s
 			}
 		}
 	}
-	if len(overrides) > 0 {
-		overrides = append([]string{"hostname " + username + "@" + hostname_for_match}, overrides...)
-	}
 	return
 }