SharedGraphics: Fix broken clipping in draw_bitmap().

SharedGraphics/Painter.cpp

@@ -160,17 +160,19 @@ void Painter::draw_bitmap(const Point& p, const CharacterBitmap& bitmap, Color c
     Rect rect { p, bitmap.size() };
     rect.move_by(m_translation);
     auto clipped_rect = Rect::intersection(rect, m_clip_rect);
+    if (clipped_rect.is_empty())
+        return;
     const int first_row = clipped_rect.top() - rect.top();
     const int last_row = clipped_rect.bottom() - rect.top();
     const int first_column = clipped_rect.left() - rect.left();
     const int last_column = clipped_rect.right() - rect.left();
-    RGBA32* dst = m_target->scanline(rect.y() + first_row) + rect.x();
+    RGBA32* dst = m_target->scanline(clipped_rect.y()) + clipped_rect.x();
     const size_t dst_skip = m_target->width();
-    const char* bitmap_row = &bitmap.bits()[first_row];
+    const char* bitmap_row = &bitmap.bits()[first_row * bitmap.width() + first_column];
     const size_t bitmap_skip = bitmap.width();
 
     for (int row = first_row; row <= last_row; ++row) {
-        for (int j = first_column; j <= last_column; ++j) {
+        for (int j = 0; j <= (last_column - first_column); ++j) {
             char fc = bitmap_row[j];
             if (fc == '#')
                 dst[j] = color.value();