made a declaration more obvious and with more detailed explanation

match formatting to the project.

src/main/java/gregtech/api/capability/impl/AbstractRecipeLogic.java

@@ -109,7 +109,7 @@ public void update() {
                     updateRecipeProgress();
                 }
                 //check everything that would make a recipe never start here.
-                if (progressTime == 0 && shouldSearchForRecipes()){
+                if (progressTime == 0 && shouldSearchForRecipes()) {
                     trySearchNewRecipe();
                 }
             }
@@ -127,14 +127,19 @@ protected boolean shouldSearchForRecipes() {
     protected boolean canFitNewOutputs() {
         // if the output is full check if the output changed so we can process recipes results again.
         if (this.isOutputsFull && !metaTileEntity.isOutputsDirty()) return false;
-        else { this.isOutputsFull = false; metaTileEntity.setOutputsDirty(false); }
+        else {
+            this.isOutputsFull = false;
+            metaTileEntity.setOutputsDirty(false);
+        }
         return true;
     }
 
     protected boolean canWorkWithInputs() {
         // if the inputs were bad last time, check if they've changed before trying to find a new recipe.
         if (this.invalidInputsForRecipes && !metaTileEntity.isInputsDirty()) return false;
-        else { this.invalidInputsForRecipes = false; }
+        else {
+            this.invalidInputsForRecipes = false;
+        }
         return true;
     }
 
@@ -175,11 +180,14 @@ protected void trySearchNewRecipe() {
             currentRecipe = findRecipe(maxVoltage, importInventory, importFluids);
         }
         // If a recipe was found, then inputs were valid.
-        // recipe multiplying machines may not be able to fit
-        // the multiplied recipes. in that case the inputs are valid
-        if (!(this.invalidInputsForRecipes = (currentRecipe == null && !this.isOutputsFull)))
-            // replace old recipe with new one
+        if (currentRecipe != null) {
+            this.invalidInputsForRecipes = false;
             this.previousRecipe = currentRecipe;
+        // Add-ons may Override findRecipe method but not trySearchNewRecipe, in that case
+        // they may return a null recipe. Since we only check for items and fluid here, having
+        // findRecipe return a null recipe with isOutputsFull being true, means we have a valid
+        // recipe in the input waiting for space in the output.
+        } else this.invalidInputsForRecipes = !this.isOutputsFull;
 
         // proceed if we have a usable recipe.
         if (currentRecipe != null && setupAndConsumeRecipeInputs(currentRecipe)) {

src/main/java/gregtech/api/capability/impl/NotifiableFluidTank.java

@@ -24,7 +24,7 @@ protected void onContentsChanged() {
     }
 
     @Override
-    public HashSet<MetaTileEntity> getNotifiableMetaTileEntities(){
+    public HashSet<MetaTileEntity> getNotifiableMetaTileEntities() {
         return this.entitiesToNotify;
     }
 }

src/main/java/gregtech/common/metatileentities/multi/electric/MetaTileEntityMultiFurnace.java

@@ -110,7 +110,7 @@ protected void trySearchNewRecipe() {
                 //if previous recipe still matches inputs, try to use it
                 currentRecipe = previousRecipe;
             }
-            if ( currentRecipe != null)
+            if (currentRecipe != null)
                 // replace old recipe with new one
                 this.previousRecipe = currentRecipe;
 
@@ -199,7 +199,7 @@ protected Recipe findRecipe(long maxVoltage,
 
             // If there were no accepted ingredients, then there is no recipe to process.
             // the output may be filled up
-            if(recipeInputs.isEmpty() && !invalidInputsForRecipes) {
+            if (recipeInputs.isEmpty() && !invalidInputsForRecipes) {
                 //Set here to prevent recipe deadlock on world load with full output bus
                 this.isOutputsFull = true;
                 return null;