Correctly parse files without trailing newline

If the file did not have a newline character as the last character,
parseKV() would panic with an NPE. Handle the parser changes better.

Fixes #21.

config_test.go

@@ -362,3 +362,19 @@ func TestDosLinesEndingsDecode(t *testing.T) {
 		t.Errorf("expected HostName to be %q, got %q", "8.8.8.8", host)
 	}
 }
+
+func TestNoTrailingNewline(t *testing.T) {
+	us := &UserSettings{
+		userConfigFinder:   testConfigFinder("testdata/config-no-ending-newline"),
+		systemConfigFinder: nullConfigFinder,
+	}
+
+	port, err := us.GetStrict("example", "Port")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if port != "4242" {
+		t.Errorf("wrong port: got %q want 4242", port)
+	}
+}

parser.go

@@ -96,6 +96,9 @@ func (p *sshParser) parseKV() sshParserStateFn {
 	}
 	comment := ""
 	tok := p.peek()
+	if tok == nil {
+		tok = &token{typ: tokenEOF}
+	}
 	if tok.typ == tokenComment && tok.Position.Line == val.Position.Line {
 		tok = p.getToken()
 		comment = tok.val

testdata/config-no-ending-newline

@@ -0,0 +1,3 @@
+Host example
+    HostName example.com
+    Port 4242