change D semantics to clear the current directory instead of the selected one

doc/ncdu.pod

@@ -180,6 +180,10 @@ Delete the selected file or directory. An error message will be shown when the
 contents of the directory do not match or do not exist anymore on the
 filesystem.
 
+=item D
+
+Clears the current directory, deleting all of its content.
+
 =item t
 
 Toggle dirs before files when sorting.

src/browser.c

@@ -435,13 +435,8 @@ int browse_key(int ch) {
           : "Folder clearing not available for imported directories.";
         break;
       }
-      if(sel == NULL || sel == dirlist_parent)
-        break;
-      if (!(sel->flags & FF_DIR)) {
-        message = "You can only clear folders";
-      }
       info_show = 0;
-      delete_init(sel, t, 1);
+      delete_init(dirlist_par, NULL, 1);
       break;
     }
 

src/delete.c

@@ -249,8 +249,11 @@ void delete_process() {
   delete_dir(root);
   if(nextsel)
     nextsel->flags |= FF_BSEL;
-  browse_init(par);
-  if(!_clear && nextsel)
+  if (_clear)
+    browse_init(root);
+  else
+    browse_init(par);
+  if(nextsel)
     dirlist_top(-4);
 }
 

src/help.c

@@ -32,7 +32,7 @@
 int page, start;
 
 
-#define KEYS 16
+#define KEYS 17
 char *keys[KEYS*2] = {
 /*|----key----|  |----------------description----------------|*/
         "up, k", "Move cursor up",
@@ -43,6 +43,7 @@ char *keys[KEYS*2] = {
             "s", "Sort by size (ascending/descending)",
             "C", "Sort by items (ascending/descending)",
             "d", "Delete selected file or directory",
+            "D", "Clears the files in the current directory",
             "t", "Toggle dirs before files when sorting",
             "g", "Show percentage and/or graph",
             "a", "Toggle between apparent size and disk usage",