Fix potential out of bounds map layout read

CHANGELOG.md

@@ -16,6 +16,7 @@ and this project somewhat adheres to [Semantic Versioning](https://semver.org/sp
    - Previously, the middle mouse button could be used as a shortcut with the pencil tool to switch to bucket-fill mode. This is now achieved using the `Alt` key.
 
 ### Fixed
+- Fix potential crash when painting and the cursor leaves the map area.
 - Fix rare crash while quitting Porymap.
 - 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.

include/core/maplayout.h

@@ -125,7 +125,9 @@ public:
     bool isWithinBorderBounds(int x, int y) const;
 
     bool getBlock(int x, int y, Block *out) const;
+    bool getBlock(const QPoint& pos, Block *out) const { return getBlock(pos.x(), pos.y(), out); }
     void setBlock(int x, int y, Block block, bool enableScriptCallback = false);
+    void setBlock(const QPoint& pos, Block block, bool enableScriptCallback = false) { setBlock(pos.x(), pos.y(), block, enableScriptCallback); }
     void setBlockdata(Blockdata blockdata, bool enableScriptCallback = false);
 
     uint16_t getMetatileId(int x, int y) const;

src/editor.cpp

@@ -1244,28 +1244,27 @@ void Editor::onMapHoverCleared() {
 }
 
 void Editor::setStatusFromMapPos(const QPoint &pos) {
-    int x = pos.x();
-    int y = pos.y();
+    Block block;
+    if (!this->layout || !this->layout->getBlock(pos, &block)) {
+        ui->statusBar->clearMessage();
+        return;
+    }
+
     if (this->editMode == EditMode::Metatiles) {
-        int blockIndex = y * layout->getWidth() + x;
-        int metatileId = layout->blockdata.at(blockIndex).metatileId();
         this->ui->statusBar->showMessage(QString("X: %1, Y: %2, %3, Scale = %4x")
-                              .arg(x)
-                              .arg(y)
-                              .arg(getMetatileDisplayMessage(metatileId))
+                              .arg(pos.x())
+                              .arg(pos.y())
+                              .arg(getMetatileDisplayMessage(block.metatileId()))
                               .arg(QString::number(zoomLevels[this->scaleIndex], 'g', 2)));
     } else if (this->editMode == EditMode::Collision) {
-        int blockIndex = y * layout->getWidth() + x;
-        uint16_t collision = layout->blockdata.at(blockIndex).collision();
-        uint16_t elevation = layout->blockdata.at(blockIndex).elevation();
         this->ui->statusBar->showMessage(QString("X: %1, Y: %2, %3")
-                              .arg(x)
-                              .arg(y)
-                              .arg(this->getMovementPermissionText(collision, elevation)));
+                              .arg(pos.x())
+                              .arg(pos.y())
+                              .arg(this->getMovementPermissionText(block.collision(), block.elevation())));
     } else if (this->editMode == EditMode::Events) {
         this->ui->statusBar->showMessage(QString("X: %1, Y: %2, Scale = %3x")
-                              .arg(x)
-                              .arg(y)
+                              .arg(pos.x())
+                              .arg(pos.y())
                               .arg(QString::number(zoomLevels[this->scaleIndex], 'g', 2)));
     }
 }