import bus optimization

src/main/java/appeng/parts/automation/PartImportBus.java

@@ -219,8 +219,9 @@ public class PartImportBus extends PartSharedItemBus implements IInventoryDestin
 	{
 		final int toSend = this.calculateMaximumAmountToImport( myAdaptor, whatToImport, inv, fzMode );
 
-		if( toSend == 0 ){
+		if( toSend == 0 )
-			return false;
+		{
+			return true;
 		}
 
 		final ItemStack newItems;
@@ -291,9 +292,14 @@ public class PartImportBus extends PartSharedItemBus implements IInventoryDestin
 			itemAmountNotStorable = inv.injectItems( AEItemStack.fromItemStack( simResult ), Actionable.SIMULATE, this.source );
 		}
 
+		if( simResult.isEmpty() )
+		{
+			return 0;
+		}
+
 		if( itemAmountNotStorable != null )
 		{
-			if (simResult.getCount() == itemAmountNotStorable.getStackSize())
+			if( simResult.getCount() == itemAmountNotStorable.getStackSize() )
 			{
 				return 0;
 			}

src/main/java/appeng/parts/misc/ItemRepositoryAdapter.java

@@ -72,8 +72,24 @@ class ItemRepositoryAdapter implements IMEInventory<IAEItemStack>, IBaseMonitor<
         if( type == Actionable.MODULATE )
         {
             if (this.cache.cachedAeStacks.length == 0) this.cache.update();
-            this.cache.cachedAeStacks = Arrays.copyOf( this.cache.cachedAeStacks, this.cache.cachedAeStacks.length + 1 );
+            boolean found = false;
-            this.cache.cachedAeStacks[this.cache.cachedAeStacks.length - 1] = iox.copy();
+            for (IAEItemStack iaeItemStack : this.cache.cachedAeStacks)
+            {
+                if( iaeItemStack == null )
+                {
+                    continue;
+                }
+                if( iaeItemStack.equals( iox ) )
+                {
+                    found = true;
+                    iaeItemStack.incStackSize( iox.getStackSize() );
+                }
+            }
+            if (!found)
+            {
+                this.cache.cachedAeStacks = Arrays.copyOf( this.cache.cachedAeStacks, this.cache.cachedAeStacks.length + 1 );
+                this.cache.cachedAeStacks[this.cache.cachedAeStacks.length - 1] = iox.copy();
+            }
         }
 
         return AEItemStack.fromItemStack( remaining );