keep empty numerical input slots in custom blocks empty when relabelling

instead of filling in zeroes

HISTORY.md

@@ -31,6 +31,7 @@
     * "relabel" blocks with translated drop-down choices
     * transforming arrayed to linked lists without loosing the last element
     * using "inherit" no longer un-hides the palette in presentation mode
+    * relabelling custom blocks with empty numerical input slots no longer fills in zeroes
 * Translation Updates:
     * Chinese, thanks, Simon!
     * Turkish, thanks, Turgut!
@@ -38,6 +39,9 @@
     * Greek, thanks, Alexandros!
     * German
 
+### 2019-02-07
+* BYOB: keep empty numerical input slots in custom blocks empty when relabelling
+
 ### 2019-02-07
 * Store: tweaked loading mechanism to enable command blocks inside reporter rings
 * Objects: tweaked spec for settings getter

snap.html

@@ -12,7 +12,7 @@
         <script type="text/javascript" src="src/gui.js?version=2019-02-07"></script>
         <script type="text/javascript" src="src/paint.js?version=2018-10-02"></script>
         <script type="text/javascript" src="src/lists.js?version=2019-02-07"></script>
-        <script type="text/javascript" src="src/byob.js?version=2019-02-06"></script>
+        <script type="text/javascript" src="src/byob.js?version=2019-02-14"></script>
         <script type="text/javascript" src="src/tables.js?version=2019-02-07"></script>
         <script type="text/javascript" src="src/symbols.js?version=2019-01-14"></script>
         <script type="text/javascript" src="src/sketch.js?version=2018-10-02"></script>

src/byob.js

@@ -108,7 +108,7 @@ BooleanSlotMorph, XML_Serializer, SnapTranslator*/
 
 // Global stuff ////////////////////////////////////////////////////////
 
-modules.byob = '2019-February-06';
+modules.byob = '2019-February-14';
 
 // Declarations
 
@@ -678,7 +678,9 @@ CustomCommandBlockMorph.prototype.restoreInputs = function (oldInputs) {
             myself.silentReplaceInput(inp, old.fullCopy());
         } else if (old instanceof InputSlotMorph
                 && inp instanceof InputSlotMorph) {
-            inp.setContents(old.evaluate());
+            if (!old.isEmptySlot()) {
+                inp.setContents(old.evaluate());
+            }
         } else if (old instanceof BooleanSlotMorph
                 && inp instanceof BooleanSlotMorph) {
             inp.setContents(old.evaluate());