Fix new tileset directory collisions

CHANGELOG.md

@@ -25,6 +25,7 @@ and this project somewhat adheres to [Semantic Versioning](https://semver.org/sp
 - Fix `Edit > Clear Map Entries` in the Region Map Editor not saving the applied changes.
 - Fix `Edit > Undo/Redo` appearing enabled even when they don't do anything.
 - Fix `Help > Open Manual` being disabled when no project is open.
+- Fix new tilesets potentially overwriting data in an existing directory.
 - Fix exported images on macOS using a different color space than in Porymap.
 - Fix some `INCBIN` statements not being parsed correctly.
 - Fix excessive logging if Porymap fails to monitor all map files.

include/core/utility.h

@@ -19,6 +19,7 @@ namespace Util {
     QString toStylesheetString(const QFont &font);
     void show(QWidget *w);
     QColorSpace toColorSpace(int colorSpaceInt);
+    QString mkpath(const QString& dirPath);
 }
 
 #endif // UTILITY_H

src/core/utility.cpp

@@ -3,6 +3,7 @@
 #include <QCollator>
 #include <QRegularExpression>
 #include <QFileInfo>
+#include <QDir>
 
 // Sometimes we want to sort names alphabetically to make them easier to find in large combo box lists.
 // QStringList::sort (as of writing) can only sort numbers in lexical order, which has an undesirable
@@ -145,3 +146,17 @@ QColorSpace Util::toColorSpace(int colorSpaceInt) {
         return QColorSpace();
     }
 }
+
+// Creates a directory named 'dirPath', including any non-existent parent directories. Returns an error message, if any.
+// If 'dirPath' already exists it's considered an error unless the directory has no files.
+QString Util::mkpath(const QString& dirPath) {
+    if (!QDir::root().mkpath(dirPath)) {
+        return QString("Failed to create directory '%1'").arg(dirPath);
+    }
+    QDir dir(dirPath);
+    QStringList files = dir.entryList(QDir::Files | QDir::NoDotAndDotDot);
+    if (!files.isEmpty()) {
+        return QString("Directory '%1' already exists and is not empty").arg(dirPath);
+    }
+    return QString();
+}

src/project.cpp

@@ -1569,17 +1569,14 @@ Tileset *Project::createNewTileset(QString name, bool secondary, bool checkerboa
 
     // Create tileset directories
     const QString fullDirectoryPath = QString("%1/%2").arg(this->root).arg(tileset->getExpectedDir());
-    QDir directory;
-    if (!directory.mkpath(fullDirectoryPath)) {
-        logError(QString("Failed to create directory '%1' for new tileset '%2'").arg(fullDirectoryPath).arg(tileset->name));
-        delete tileset;
-        return nullptr;
-    }
     const QString palettesPath = fullDirectoryPath + "/palettes";
-    if (!directory.mkpath(palettesPath)) {
-        logError(QString("Failed to create palettes directory '%1' for new tileset '%2'").arg(palettesPath).arg(tileset->name));
-        delete tileset;
-        return nullptr;
+    for (const auto& dir : {fullDirectoryPath, palettesPath}) {
+        QString error = Util::mkpath(dir);
+        if (!error.isEmpty()) {
+            logError(QString("Failed to create tileset '%1': %2.").arg(tileset->name).arg(error));
+            delete tileset;
+            return nullptr;
+        }
     }
 
     tileset->tilesImagePath = fullDirectoryPath + "/tiles.png";