Avoid div by zero by preventing entering/returning a grid bounds w/zero width/height (fix #4146, #4597)

src/app/commands/cmd_grid.cpp

@@ -114,6 +114,16 @@ void GridSettingsCommand::onExecute(Context* context)
   window.gridY()->setTextf("%d", bounds.y);
   window.gridW()->setTextf("%d", bounds.w);
   window.gridH()->setTextf("%d", bounds.h);
+  window.gridW()->Leave.connect([&window]{
+    // Prevent entering a width lesser than 1
+    if (window.gridW()->textInt() <= 0)
+      window.gridW()->setText("1");
+  });
+  window.gridH()->Leave.connect([&window]{
+    // Prevent entering a height lesser than 1
+    if (window.gridH()->textInt() <= 0)
+      window.gridH()->setText("1");
+  });
   window.openWindowInForeground();
 
   if (window.closer() == window.ok()) {

src/app/commands/cmd_options.cpp

@@ -320,6 +320,18 @@ public:
     }
     cursorColorType()->Change.connect([this]{ onCursorColorType(); });
 
+    // Grid
+    gridW()->Leave.connect([this] {
+      // Prevent entering a width lesser than 1
+      if (gridW()->textInt() <= 0)
+        gridW()->setText("1");
+    });
+    gridH()->Leave.connect([this] {
+      // Prevent entering a height lesser than 1
+      if (gridH()->textInt() <= 0)
+        gridH()->setText("1");
+    });
+
     // Brush preview
     brushPreview()->setSelectedItemIndex(
       (int)m_pref.cursor.brushPreview());

src/app/ui/expr_entry.cpp

@@ -35,6 +35,8 @@ bool ExprEntry::onProcessMessage(ui::Message* msg)
       onFormatExprFocusLeave(buf);
       if (text() != buf)
         setText(buf);
+
+      Leave();
       break;
     }
   }

src/app/ui/expr_entry.h

@@ -20,6 +20,9 @@ namespace app {
     int decimals() const { return m_decimals; }
     void setDecimals(int decimals) { m_decimals = decimals; }
 
+    // Signals
+    obs::signal<void()> Leave;
+
   protected:
     bool onProcessMessage(ui::Message* msg) override;
     void onChange() override;

src/doc/sprite.cpp

@@ -49,6 +49,11 @@ gfx::Rect Sprite::DefaultGridBounds()
 void Sprite::SetDefaultGridBounds(const gfx::Rect& defGridBounds)
 {
   g_defaultGridBounds = defGridBounds;
+  // Prevent setting an empty grid bounds
+  if (g_defaultGridBounds.w <= 0)
+    g_defaultGridBounds.w = 1;
+  if (g_defaultGridBounds.h <= 0)
+    g_defaultGridBounds.h = 1;
 }
 
 // static

src/doc/sprite.h

@@ -127,7 +127,14 @@ namespace doc {
     static void SetDefaultRgbMapAlgorithm(const RgbMapAlgorithm mapAlgo);
 
     const gfx::Rect& gridBounds() const { return m_gridBounds; }
-    void setGridBounds(const gfx::Rect& rc) { m_gridBounds = rc; }
+    void setGridBounds(const gfx::Rect& rc) {
+      m_gridBounds = rc;
+      // Prevent setting an empty grid bounds
+      if (m_gridBounds.w <= 0)
+        m_gridBounds.w = 1;
+      if (m_gridBounds.h <= 0)
+        m_gridBounds.h = 1;
+    }
 
     virtual int getMemSize() const override;