Allow creating an empty PNAMES directory.

src/help/pnames_editor.md

@@ -37,3 +37,9 @@ All [standard controls](common.md) are also supported.
    line. If none are tagged, the file will contain the entire list.
  * To import such a file into the texture directory, select the file in the
    [opposite pane](dir_view.md) and use **Import config (F5)**.
+
+## Creating a new PNAMES directory
+
+To create a new PNAMES directory, simply create an empty lump named PNAMES and
+open it; a pop-up notice will confirm that a new PNAMES directory has been
+created.

src/textures/pnames_dir.c

@@ -165,7 +165,15 @@ static bool PnamesDirLoad(void *_dir, struct directory *wad_dir,
                           struct directory_entry *ent)
 {
 	struct pnames_dir *dir = _dir;
-	VFILE *in = VFS_OpenByEntry(wad_dir, ent);
+	VFILE *in;
+	if (ent->size == 0) {
+		UI_ShowNotice("Creating a new, empty PNAMES directory.");
+		dir->dir.b.txs = NULL;
+		PNAMES(dir) = TX_NewPnamesList(0);
+		++PNAMES(dir)->modified_count;
+		return true;
+	}
+	in = VFS_OpenByEntry(wad_dir, ent);
 	return TX_BundleLoadPnames(&dir->dir.b, in);
 }