qt: Create addons directory if it does not exist. (shadps4-emu#1186)

Author: squidbus

src/common/path_util.h

@@ -44,7 +44,6 @@ constexpr auto DOWNLOAD_DIR = "download";
 constexpr auto CAPTURES_DIR = "captures";
 constexpr auto CHEATS_DIR = "cheats";
 constexpr auto PATCHES_DIR = "patches";
-constexpr auto ADDONS_DIR = "addcont";
 constexpr auto METADATA_DIR = "game_data";
 
 // Filenames

src/qt_gui/game_install_dialog.cpp

@@ -111,12 +111,19 @@ void GameInstallDialog::Save() {
         return;
     }
 
-    if (addonsDirectory.isEmpty() || !QDir(addonsDirectory).exists() ||
-        !QDir::isAbsolutePath(addonsDirectory)) {
+    if (addonsDirectory.isEmpty() || !QDir::isAbsolutePath(addonsDirectory)) {
         QMessageBox::critical(this, tr("Error"),
                               "The value for location to install DLC is not valid.");
         return;
     }
+    QDir addonsDir(addonsDirectory);
+    if (!addonsDir.exists()) {
+        if (!addonsDir.mkpath(".")) {
+            QMessageBox::critical(this, tr("Error"),
+                                  "The DLC install location could not be created.");
+            return;
+        }
+    }
 
     Config::setGameInstallDir(Common::FS::PathFromQString(gamesDirectory));
     Config::setAddonInstallDir(Common::FS::PathFromQString(addonsDirectory));