Ticket #1894: sort order should not mix hidden files with others.

In case sensitive sort, the order of files and directories is following:
hidden dirs
dirs
hidden files
files

In case insensitive mode, directories are mixed and files are mixed too:
dirs (hidden and not are mixed)
files (hidden and not are mixed).

This commit defines the sort order independently of case sensitivity:
hidden dirs
dirs
hidden files
files

Files in UTF-8 locale require special handling: leading dot must not be
processed in g_utf8_casefold() funcion.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>

lib/strutil/strutilutf8.c

@@ -1220,18 +1220,29 @@ str_utf8_caseprefix (const char *text, const char *prefix)
 
 static char *
 str_utf8_create_key_gen (const char *text, int case_sen,
-			 gchar * (*keygen) (const gchar *, gssize size))
+			 gchar * (*keygen) (const gchar *text, gssize size))
 {
     char *result;
     
     if (case_sen) {
         result = str_utf8_normalize (text);
     } else {
+        gboolean dot;
+        GString *fixed;
         const char *start, *end;
         char *fold, *key;
-        GString *fixed = g_string_new ("");
 
+        dot = text[0] == '.';
+        fixed = g_string_sized_new (16);
+
+        if (!dot)
             start = text;
+        else
+        {
+            start = text + 1;
+            g_string_append_c (fixed, '.');
+        }
+
         while (!g_utf8_validate (start, -1, &end) && start[0] != '\0')
         {
             if (start != end)
@@ -1248,9 +1259,19 @@ str_utf8_create_key_gen (const char *text, int case_sen,
 
         if (start == text)
         {
-            fold = g_utf8_casefold (text, -1);
+            fold = g_utf8_casefold (start, -1);
             result = keygen (fold, -1);
             g_free (fold);
+            g_string_free (fixed, TRUE);
+        }
+        else if (dot && (start == text + 1))
+        {
+            fold = g_utf8_casefold (start, -1);
+            key = keygen (fold, -1);
+            g_string_append (fixed, key);
+            g_free (key);
+            g_free (fold);
+            result = g_string_free (fixed, FALSE);
         }
         else
         {
@@ -1262,9 +1283,8 @@ str_utf8_create_key_gen (const char *text, int case_sen,
                 g_free (key);
                 g_free (fold);
             }
-            result = g_strdup (fixed->str);
+            result = g_string_free (fixed, FALSE);
         }
-        g_string_free (fixed, TRUE);
     }
     return result;
 }

src/dir.c

@@ -63,6 +63,33 @@ sort_orders_t sort_orders [SORT_TYPES_TOTAL] = {
 };
 */
 
+static inline int
+key_collate (const char *t1, const char *t2)
+{
+    int dotdot = 0;
+    int ret;
+
+    dotdot = (t1[0] == '.' ? 1 : 0) | ((t2[0] == '.' ? 1 : 0) << 1);
+
+    switch (dotdot)
+    {
+       case 0:
+       case 3:
+           ret = str_key_collate (t1, t2, case_sensitive) * reverse;
+           break;
+       case 1:
+           ret = -1; /* t1 < t2 */
+           break;
+       case 2:
+           ret = 1; /* t1 > t2 */
+           break;
+       default:
+           ret = 0; /* it must not happen */
+    }
+
+    return ret;
+}
+
 int
 unsorted (file_entry *a, file_entry *b)
 {
@@ -84,8 +111,7 @@ sort_name (file_entry *a, file_entry *b)
         if (b->sort_key == NULL)
             b->sort_key = str_create_key_for_filename (b->fname, case_sensitive);
 
-	return str_key_collate (a->sort_key, b->sort_key, case_sensitive) 
+	return key_collate (a->sort_key, b->sort_key);
-                * reverse;
     }
     return bd - ad;
 }