Make the outer prompt look more normal

There's a slight issue with the inverted cell representing
the cursor standing out a bit too much amongst the rest of
the characters.

The resulting experience is a lot more consistent, though.

README.adoc

@@ -55,7 +55,7 @@ To start using this navigator, put the following in your '.zshrc':
 ----
 sdn-navigate () {
   # ... possibly zle-line-init
-  while eval "`sdn`"; do
+  while eval "`sdn "$BUFFER" "$CURSOR"`"; do
     [ -z "$cd" ] || cd "$cd"
     [ -z "$insert" ] || LBUFFER="$LBUFFER$insert "
     [ -z "$helper" ] && break
@@ -74,7 +74,9 @@ To start using this navigator, put the following in your 'config.fish':
 ----
 function sdn-navigate
   set --local IFS
-  while eval (sdn | string replace -ar '^(.*?)=' 'set --$1 ')
+  set --local buffer (commandline)
+  set --local cursor (commandline --cursor)
+  while eval (sdn $buffer $cursor | string replace -ar '^(.*?)=' 'set --$1 ')
     test -z "$cd" || cd "$cd"
     test -z "$insert" || commandline --insert "$insert "
     test -z "$helper" && break
@@ -96,7 +98,7 @@ sdn-navigate () {
   SDN_L=$READLINE_LINE SDN_P=$READLINE_POINT
   READLINE_LINE=
 
-  while eval "`sdn`"; do
+  while eval "`sdn "$SDN_L" "$SDN_P"`"; do
     [[ -z "$cd" ]] || cd "$cd"
     [[ -z "$insert" ]] || {
       SDN_L="${SDN_L:0:$SDN_P}$insert ${SDN_L:$SDN_P}"
@@ -129,6 +131,7 @@ cursor 231 202
 bar 16 255 ul
 cwd bold
 input
+cmdline 145
 ....
 
 Filename colours are taken from the `LS_COLORS` environment variable.

sdn.cpp

@@ -495,6 +495,7 @@ struct level {
 };
 
 static struct {
+	ncstring cmdline;                   ///< Outer command line
 	string cwd;                         ///< Current working directory
 	string start_dir;                   ///< Starting directory
 	vector<entry> entries;              ///< Current directory entries
@@ -525,9 +526,10 @@ static struct {
 	void (*editor_on_change) ();        ///< Callback on editor change
 	void (*editor_on_confirm) ();       ///< Callback on editor confirmation
 
-	enum { AT_CURSOR, AT_BAR, AT_CWD, AT_INPUT, AT_COUNT };
-	chtype attrs[AT_COUNT] = {A_REVERSE, 0, A_BOLD, 0};
-	const char *attr_names[AT_COUNT] = {"cursor", "bar", "cwd", "input"};
+	enum { AT_CURSOR, AT_BAR, AT_CWD, AT_INPUT, AT_CMDLINE, AT_COUNT };
+	chtype attrs[AT_COUNT] = {A_REVERSE, 0, A_BOLD, 0, 0};
+	const char *attr_names[AT_COUNT] =
+		{"cursor", "bar", "cwd", "input", "cmdline"};
 
 	map<int, chtype> ls_colors;         ///< LS_COLORS decoded
 	map<string, chtype> ls_exts;        ///< LS_COLORS file extensions
@@ -746,6 +748,9 @@ fun update () {
 	} else if (!g.message.empty ()) {
 		move (LINES - 1, 0);
 		print (apply_attrs (g.message, 0), COLS);
+	} else if (!g.cmdline.empty ()) {
+		move (LINES - 1, 0);
+		print (g.cmdline, COLS);
 	}
 
 	refresh ();
@@ -1352,6 +1357,20 @@ fun inotify_check () {
 		update ();
 }
 
+fun load_cmdline (int argc, char *argv[]) {
+	if (argc < 3)
+		return;
+
+	wstring line = to_wide (argv[1]); int cursor = atoi (argv[2]);
+	if (line.empty () || cursor < 0 || cursor > (int) line.length ())
+		return;
+
+	std::replace_if (begin (line), end (line), iswspace, L' ');
+	g.cmdline = apply_attrs (line += L' ', g.attrs[g.AT_CMDLINE]);
+	// It is tempting to touch the cchar_t directly, though let's rather not
+	g.cmdline[cursor] = cchar (g.attrs[g.AT_CMDLINE] ^ A_REVERSE, line[cursor]);
+}
+
 fun decode_ansi_sgr (const vector<string> &v) -> chtype {
 	vector<int> args;
 	for (const auto &arg : v) {
@@ -1627,9 +1646,6 @@ fun save_config () {
 }
 
 int main (int argc, char *argv[]) {
-	(void) argc;
-	(void) argv;
-
 	// That bitch zle closes stdin before exec without redirection
 	(void) close (STDIN_FILENO);
 	if (open ("/dev/tty", O_RDWR)) {
@@ -1659,6 +1675,7 @@ int main (int argc, char *argv[]) {
 	}
 
 	load_colors ();
+	load_cmdline (argc, argv);
 	g.start_dir = g.cwd = initial_cwd ();
 	reload (false);
 	pop_levels (g.cwd);