Blocks: Set function with return call block type

The function call block now checks what the return type of the function
definition block is, in order to determine its own type.

Also, fixes issue where some blocks had block inputs attached but no
connections (caused by mutations editing the available inputs).

Author: carlosperate

blockly/blocks/procedures.js

@@ -772,7 +772,14 @@ Blockly.Blocks['procedures_callreturn'] = {
   mutationToDom: Blockly.Blocks['procedures_callnoreturn'].mutationToDom,
   domToMutation: Blockly.Blocks['procedures_callnoreturn'].domToMutation,
   renameVar: Blockly.Blocks['procedures_callnoreturn'].renameVar,
-  customContextMenu: Blockly.Blocks['procedures_callnoreturn'].customContextMenu
+  customContextMenu:
+      Blockly.Blocks['procedures_callnoreturn'].customContextMenu,
+  /** @return {!string} Return value type from the function definition block. */
+  getBlockType: function() {
+    var defBlock = Blockly.Procedures.getDefinition(this.getProcedureCall(),
+        this.workspace);
+    return defBlock.getReturnType();
+  }
 };
 
 Blockly.Blocks['procedures_ifreturn'] = {

blockly/core/types.js

@@ -166,7 +166,8 @@ Blockly.Types.getChildBlockType = function(block) {
   // Only checks first input block, so it decides the type. Incoherences amongst
   // multiple inputs dealt at a per-block level with their own block warnings
   while (nextBlock && (nextBlock.getBlockType === undefined) &&
-         (nextBlock.inputList.length > 0)) {
+         (nextBlock.inputList.length > 0) &&
+         (nextBlock.inputList[0].connection)) {
     nextBlock = nextBlock.inputList[0].connection.targetBlock();
   }
   if (nextBlock === block) {