Port the el_fn_sh_complete from FreeBSD.
This function is required by FreeBSD-9.0's sh.
So that we can drop the bundled version in FreeBSD-9.0

diff -uNr libedit-20120311-3.0/src/filecomplete.c libedit-20120311-3.0.freebsd/src/filecomplete.c
--- libedit-20120311-3.0/src/filecomplete.c	2012-03-11 09:54:58.000000000 +0000
+++ libedit-20120311-3.0.freebsd/src/filecomplete.c	2012-04-23 12:14:25.000000000 +0000
@@ -56,6 +56,9 @@
 
 static const Char break_chars[] = { ' ', '\t', '\n', '"', '\\', '\'', '`', '@',
     '$', '>', '<', '=', ';', '|', '&', '{', '(', '\0' };
+/* Tilde is deliberately omitted here, we treat it specially. */
+static const Char extra_quote_chars[] = { ')', '}', '*', '?', '[', '$', '\0' };
+
 
 
 /********************************/
@@ -411,10 +414,14 @@
 	char **(*attempted_completion_function)(const char *, int, int),
 	const Char *word_break, const Char *special_prefixes,
 	const char *(*app_func)(const char *), size_t query_items,
-	int *completion_type, int *over, int *point, int *end)
+	int *completion_type, int *over, int *point, int *end,
+	const char *(*find_word_start_func)(const char *, const char *),
+	char *(*dequoting_func)(const char *),
+	char *(*quoting_func)(const char *))
 {
 	const TYPE(LineInfo) *li;
 	Char *temp;
+	char *dequoted_temp;
         char **matches;
 	const Char *ctemp;
 	size_t len;
@@ -435,17 +442,28 @@
 
 	/* We now look backwards for the start of a filename/variable word */
 	li = FUN(el,line)(el);
+	if (find_word_start_func)
+		ctemp = ct_decode_string(find_word_start_func(ct_encode_string(li->buffer,&el->el_scratch), ct_encode_string(li->cursor,&el->el_scratch)),&el->el_scratch);
+	else {
 	ctemp = li->cursor;
 	while (ctemp > li->buffer
 	    && !Strchr(word_break, ctemp[-1])
 	    && (!special_prefixes || !Strchr(special_prefixes, ctemp[-1]) ) )
 		ctemp--;
+	}
 
 	len = (size_t)(li->cursor - ctemp);
 	temp = el_malloc((len + 1) * sizeof(*temp));
 	(void)Strncpy(temp, ctemp, len);
 	temp[len] = '\0';
 
+	if (dequoting_func) {
+		dequoted_temp = dequoting_func(ct_encode_string(temp,&el->el_scratch));
+		if (dequoted_temp == NULL)
+			return retval;
+	} else
+		dequoted_temp = NULL;
+
 	/* these can be used by function called in completion_matches() */
 	/* or (*attempted_completion_function)() */
 	if (point != 0)
@@ -456,14 +474,14 @@
 	if (attempted_completion_function) {
 		int cur_off = (int)(li->cursor - li->buffer);
 		matches = (*attempted_completion_function)(
-		    ct_encode_string(temp, &el->el_scratch),
+		    dequoted_temp? dequoted_temp : ct_encode_string(temp, &el->el_scratch),
 		    cur_off - (int)len, cur_off);
 	} else
 		matches = 0;
 	if (!attempted_completion_function || 
 	    (over != NULL && !*over && !matches))
 		matches = completion_matches(
-		    ct_encode_string(temp, &el->el_scratch), complet_func);
+		    dequoted_temp? dequoted_temp : ct_encode_string(temp, &el->el_scratch), complet_func);
 
 	if (over != NULL)
 		*over = 0;
@@ -478,9 +496,19 @@
 		 * possible matches if there is possible completion.
 		 */
 		if (matches[0][0] != '\0') {
+			char *quoted_match;
+			if (quoting_func) {
+				quoted_match = quoting_func(matches[0]);
+				if (quoted_match == NULL)
+					goto free_matches;
+			} else
+				quoted_match = NULL;
+
 			el_deletestr(el, (int) len);
 			FUN(el,insertstr)(el,
-			    ct_decode_string(matches[0], &el->el_scratch));
+			    ct_decode_string(quoted_match? quoted_match : matches[0], &el->el_scratch));
+
+			free(quoted_match);
 		}
 
 		if (what_to_do == '?')
@@ -553,12 +581,14 @@
 			retval = CC_NORM;
 		}
 
+free_matches:
 		/* free elements of array and the array itself */
 		for (i = 0; matches[i]; i++)
 			el_free(matches[i]);
 		el_free(matches);
 		matches = NULL;
 	}
+	el_free(dequoted_temp);
 	el_free(temp);
 	return retval;
 }
@@ -572,5 +602,102 @@
 {
 	return (unsigned char)fn_complete(el, NULL, NULL,
 	    break_chars, NULL, NULL, (size_t)100,
-	    NULL, NULL, NULL, NULL);
+	    NULL, NULL, NULL, NULL,
+	    NULL, NULL, NULL);
+}
+
+static const char *
+sh_find_word_start(const char *buffer, const char *cursor)
+{
+	const char *word_start = buffer;
+
+	while (buffer < cursor) {
+		if (*buffer == '\\')
+			buffer++;
+		else if (Strchr(break_chars, *buffer))
+			word_start = buffer + 1;
+
+		buffer++;
+	}
+
+	return word_start;
+}
+
+
+static char *
+sh_quote(const char *str)
+{
+	const char *src;
+	int extra_len = 0;
+	char *quoted_str, *dst;
+
+	if (*str == '-' || *str == '+')
+		extra_len += 2;
+	for (src = str; *src != '\0'; src++)
+		if (Strchr(break_chars, *src) ||
+		    Strchr(extra_quote_chars, *src))
+			extra_len++;
+
+	quoted_str = malloc(sizeof(*quoted_str) *
+	    (strlen(str) + extra_len + 1));
+	if (quoted_str == NULL)
+		return NULL;
+
+	dst = quoted_str;
+	if (*str == '-' || *str == '+')
+		*dst++ = '.', *dst++ = '/';
+	for (src = str; *src != '\0'; src++) {
+		if (Strchr(break_chars, *src) ||
+		    Strchr(extra_quote_chars, *src))
+			*dst++ = '\\';
+		*dst++ = *src;
+	}
+	*dst = '\0';
+
+	return quoted_str;
+}
+
+
+static char *
+sh_dequote(const char *str)
+{
+	char *dequoted_str, *dst;
+
+	/* save extra space to replace \~ with ./~ */
+	dequoted_str = malloc(sizeof(*dequoted_str) * (strlen(str) + 1 + 1));
+	if (dequoted_str == NULL)
+		return NULL;
+
+	dst = dequoted_str;
+
+	/* dequote \~ at start as ./~ */
+	if (*str == '\\' && str[1] == '~') {
+		str++;
+		*dst++ = '.';
+		*dst++ = '/';
+	}
+
+	while (*str) {
+		if (*str == '\\')
+			str++;
+		if (*str)
+			*dst++ = *str++;
+	}
+	*dst = '\0';
+
+	return dequoted_str;
+}
+
+
+/*
+ * completion function using sh quoting rules; for key binding
+ */
+/* ARGSUSED */
+unsigned char
+_el_fn_sh_complete(EditLine *el, int ch __attribute__((__unused__)))
+{
+	return (unsigned char)fn_complete(el, NULL, NULL,
+	    break_chars, NULL, NULL, 100,
+	    NULL, NULL, NULL, NULL,
+	    sh_find_word_start, sh_dequote, sh_quote);
 }
diff -uNr libedit-20120311-3.0/src/filecomplete.h libedit-20120311-3.0.freebsd/src/filecomplete.h
--- libedit-20120311-3.0/src/filecomplete.h	2010-04-22 19:13:17.000000000 +0000
+++ libedit-20120311-3.0.freebsd/src/filecomplete.h	2012-04-23 12:04:12.000000000 +0000
@@ -35,7 +35,10 @@
     char *(*)(const char *, int),
     char **(*)(const char *, int, int),
     const Char *, const Char *, const char *(*)(const char *), size_t,
-    int *, int *, int *, int *);
+    int *, int *, int *, int *,
+    const char *(*)(const char *, const char *),
+    char *(*)(const char *),
+    char *(*)(const char *));
 
 void fn_display_match_list(EditLine *, char **, size_t, size_t);
 char *fn_tilde_expand(const char *);
Binary files libedit-20120311-3.0/src/filecomplete.o and libedit-20120311-3.0.freebsd/src/filecomplete.o differ
diff -uNr libedit-20120311-3.0/src/histedit.h libedit-20120311-3.0.freebsd/src/histedit.h
--- libedit-20120311-3.0/src/histedit.h	2011-08-02 06:52:08.000000000 +0000
+++ libedit-20120311-3.0.freebsd/src/histedit.h	2012-04-23 11:44:33.000000000 +0000
@@ -113,6 +113,7 @@
 int		 el_set(EditLine *, int, ...);
 int		 el_get(EditLine *, int, ...);
 unsigned char	_el_fn_complete(EditLine *, int);
+unsigned char	_el_fn_sh_complete(EditLine *, int);
 
 /*
  * el_set/el_get parameters
diff -ur libedit-20120311-3.0/src/readline.c libedit-20120311-3.0.freebsd/src/readline.c
--- libedit-20120311-3.0/src/readline.c	2012-03-11 09:54:58.000000000 +0000
+++ libedit-20120311-3.0.freebsd/src/readline.c	2012-04-23 12:20:11.000000000 +0000
@@ -1773,7 +1773,7 @@
 	    _rl_completion_append_character_function,
 	    (size_t)rl_completion_query_items,
 	    &rl_completion_type, &rl_attempted_completion_over,
-	    &rl_point, &rl_end);
+	    &rl_point, &rl_end, NULL, NULL, NULL);
 
 
 }