Index: binaries/data/mods/public/simulation/components/UnitAI.js
===================================================================
--- binaries/data/mods/public/simulation/components/UnitAI.js
+++ binaries/data/mods/public/simulation/components/UnitAI.js
@@ -2214,7 +2214,7 @@
 					"MovementUpdate": function(msg) {
 						// If it looks like the path is failing, and we are close enough (3 tiles) from wanted range
 						// stop anyways. This avoids pathing for an unreachable goal and reduces lag considerably.
-						if (msg.likelyFailure || 
+						if (msg.likelyFailure ||
 							msg.obstructed && this.RelaxedMaxRangeCheck(this.order.data, this.order.data.max + this.DefaultRelaxedMaxRange) ||
 							!msg.obstructed && this.CheckRange(this.order.data))
 							this.FinishOrder();
@@ -2224,6 +2224,36 @@
 		},
 
 		"GATHER": {
+			"enter": function()
+			{
+				let cmpSupply = Engine.QueryInterface(this.gatheringTarget, IID_ResourceSupply);
+				if (cmpSupply)
+				{
+					let resourceType = cmpSupply.GetType();
+					let cmpResourceGatherer = Engine.QueryInterface(this.entity, IID_ResourceGatherer);
+
+					// If the unit is full go to the nearest dropsite instead of trying to gather.
+					if (!cmpResourceGatherer.CanCarryMore(resourceType.generic))
+					{
+						let nearestDropsite = this.FindNearestDropsite(resourceType.generic);
+						// Oh no, couldn't find any drop sites. Give up on gathering.
+						if (!nearestDropsite)
+						{
+							this.FinishOrder();
+							return false;
+						}
+
+						this.PushOrderFront("ReturnResource", {
+							"target": nearestDropsite,
+							"force": false,
+							"type": resourceType
+						});
+					}
+
+					return true;
+				}
+				return false;
+			},
 			"leave": function() {
 				// Show the carried resource, if we've gathered anything.
 				this.SetDefaultAnimationVariant();
@@ -2233,9 +2263,10 @@
 				"enter": function() {
 					this.gatheringTarget = this.order.data.target;	// temporary, deleted in "leave".
 
+
+					let cmpSupply = Engine.QueryInterface(this.gatheringTarget, IID_ResourceSupply);
 					// Check that we can gather from the resource we're supposed to gather from.
 					let cmpOwnership = Engine.QueryInterface(this.entity, IID_Ownership);
-					let cmpSupply = Engine.QueryInterface(this.gatheringTarget, IID_ResourceSupply);
 					let cmpMirage = Engine.QueryInterface(this.gatheringTarget, IID_Mirage);
 					if ((!cmpMirage || !cmpMirage.Mirages(IID_ResourceSupply)) &&
 					    (!cmpSupply || !cmpSupply.AddGatherer(cmpOwnership.GetOwner(), this.entity)) ||
@@ -5587,7 +5618,7 @@
 	    this.workOrders.length && this.workOrders[0].type == "Trade")
 	{
 		let cmpTrader = Engine.QueryInterface(this.entity, IID_Trader);
-		if (cmpTrader.HasBothMarkets() && 
+		if (cmpTrader.HasBothMarkets() &&
 		   (cmpTrader.GetFirstMarket() == target && cmpTrader.GetSecondMarket() == source ||
 		    cmpTrader.GetFirstMarket() == source && cmpTrader.GetSecondMarket() == target))
 		{