Always check for directory changes with sendfile auto completion

Instead of only checking for files when 'last_directory' has changed, do
it every time.

Add autocomplete_update function that updates the items while retaining
last_found and search_str.

Fixes #1099

src/command/cmd_ac.c

@@ -1290,11 +1290,15 @@ cmd_ac_uninit(void)
     autocomplete_free(statusbar_show_ac);
 }
 
+static void
+_filepath_item_free(char **ptr) {
+    char *item = *ptr;
+    free(item);
+}
+
 char*
 cmd_ac_complete_filepath(const char *const input, char *const startstr, gboolean previous)
 {
-    static char* last_directory = NULL;
-
     unsigned int output_off = 0;
 
     char *result = NULL;
@@ -1339,12 +1343,9 @@ cmd_ac_complete_filepath(const char *const input, char *const startstr, gboolean
     free(inpcp);
     free(inpcp2);
 
-    if (!last_directory || strcmp(last_directory, directory) != 0) {
-        free(last_directory);
-        last_directory = directory;
-        autocomplete_reset(filepath_ac);
-
     struct dirent *dir;
+    GArray *files = g_array_new(TRUE, FALSE, sizeof(char *));
+    g_array_set_clear_func(files, (GDestroyNotify)_filepath_item_free);
 
     DIR *d = opendir(directory);
     if (d) {
@@ -1357,7 +1358,8 @@ cmd_ac_complete_filepath(const char *const input, char *const startstr, gboolean
                 // only show hidden files on explicit request
                 continue;
             }
-                char * acstring;
+
+            char *acstring;
             if (output_off) {
                 if (asprintf(&tmp, "%s/%s", directory, dir->d_name) == -1) {
                     free(foofile);
@@ -1379,16 +1381,19 @@ cmd_ac_complete_filepath(const char *const input, char *const startstr, gboolean
                     return NULL;
                 }
             }
-                autocomplete_add(filepath_ac, acstring);
+
+            char *acstring_cpy = strdup(acstring);
+            g_array_append_val(files, acstring_cpy);
             free(acstring);
         }
         closedir(d);
     }
-    } else {
     free(directory);
-    }
     free(foofile);
 
+    autocomplete_update(filepath_ac, (char **)files->data);
+    g_array_free(files, TRUE);
+
     result = autocomplete_param_with_ac(input, startstr, filepath_ac, TRUE, previous);
     if (result) {
         return result;

src/tools/autocomplete.c

@@ -66,8 +66,10 @@ void
 autocomplete_clear(Autocomplete ac)
 {
     if (ac) {
+        if (ac->items) {
             g_list_free_full(ac->items, free);
             ac->items = NULL;
+        }
 
         autocomplete_reset(ac);
     }
@@ -101,6 +103,35 @@ autocomplete_length(Autocomplete ac)
     }
 }
 
+void
+autocomplete_update(Autocomplete ac, char **items)
+{
+    gchar *last_found = NULL;
+    gchar *search_str = NULL;
+
+    if (ac->last_found) {
+        last_found = strdup(ac->last_found->data);
+    }
+
+    if (ac->search_str) {
+        search_str = strdup(ac->search_str);
+    }
+
+    autocomplete_clear(ac);
+    autocomplete_add_all(ac, items);
+
+    if (last_found) {
+        // NULL if last_found was removed on update.
+        ac->last_found = g_list_find_custom(ac->items, last_found, (GCompareFunc)strcmp);
+        free(last_found);
+    }
+
+    if (search_str) {
+        ac->search_str = strdup(search_str);
+        free(search_str);
+    }
+}
+
 void
 autocomplete_add(Autocomplete ac, const char *item)
 {

src/tools/autocomplete.h

@@ -51,6 +51,7 @@ void autocomplete_free(Autocomplete ac);
 
 void autocomplete_add(Autocomplete ac, const char *item);
 void autocomplete_add_all(Autocomplete ac, char **items);
+void autocomplete_update(Autocomplete ac, char **items);
 void autocomplete_remove(Autocomplete ac, const char *const item);
 void autocomplete_remove_all(Autocomplete ac, char **items);