fixed an edge case for slot type inferral

HISTORY.md

@@ -6,9 +6,13 @@
 * **Notable Changes:**
 * **Notable Fixes:**
     * guard against broken SVG costumes when loading a project
+    * fixed an edge case for slot type inferral
 * **Documentation Updates:**
 * **Translation Updates:**
 
+### 2022-03-11
+* blocks: fixed an edge case for slot type inferral
+
 ### 2022-03-10
 * gui: made dev-warning closeable and added official url 
 

snap.html

@@ -16,7 +16,7 @@
         <script src="src/morphic.js?version=2022-01-28"></script>
         <script src="src/symbols.js?version=2021-03-03"></script>
         <script src="src/widgets.js?version=2021-17-09"></script>
-        <script src="src/blocks.js?version=2022-03-07"></script>
+        <script src="src/blocks.js?version=2022-03-11"></script>
         <script src="src/threads.js?version=2022-03-03"></script>
         <script src="src/objects.js?version=2022-03-09"></script>
         <script src="src/scenes.js?version=2022-03-03"></script>

src/blocks.js

@@ -161,7 +161,7 @@ CostumeIconMorph, SoundIconMorph, SVG_Costume*/
 
 // Global stuff ////////////////////////////////////////////////////////
 
-modules.blocks = '2022-March-07';
+modules.blocks = '2022-March-11';
 
 var SyntaxElementMorph;
 var BlockMorph;
@@ -6670,7 +6670,7 @@ ReporterBlockMorph.prototype.determineSlotSpec = function () {
     if (this.parent instanceof TemplateSlotMorph) {
         return this.parent.getSpec();
     }
-    return null;
+    return '';
 };
 
 // ReporterBlockMorph events