Fix duplicated stacks of collapsed connected blocks.

core/block.js

@@ -273,12 +273,12 @@ Blockly.Block.prototype.getConnections_ = function(all) {
     if (this.outputConnection) {
       myConnections.push(this.outputConnection);
     }
-    if (this.nextConnection) {
-      myConnections.push(this.nextConnection);
-    }
     if (this.previousConnection) {
       myConnections.push(this.previousConnection);
     }
+    if (this.nextConnection) {
+      myConnections.push(this.nextConnection);
+    }
     if (all || !this.collapsed_) {
       for (var i = 0, input; input = this.inputList[i]; i++) {
         if (input.connection) {
@@ -518,18 +518,30 @@ Blockly.Block.prototype.setEditable = function(editable) {
  * @param {boolean} hidden True if connections are hidden.
  */
 Blockly.Block.prototype.setConnectionsHidden = function(hidden) {
+  if (!hidden && this.isCollapsed()) {
+    if (this.outputConnection) {
+      this.outputConnection.setHidden(hidden);
+    }
+    if (this.previousConnection) {
+      this.previousConnection.setHidden(hidden);
+    }
+    if (this.nextConnection) {
+      this.nextConnection.setHidden(hidden);
+      var child = this.nextConnection.targetBlock();
+      if (child) {
+        child.setConnectionsHidden(hidden);
+      }
+    }
+  } else {
     var myConnections = this.getConnections_(true);
     for (var i = 0, connection; connection = myConnections[i]; i++) {
-    if (connection.isSuperior()) {
-      if (!this.isCollapsed()) {
       connection.setHidden(hidden);
+      if (connection.isSuperior()) {
         var child = connection.targetBlock();
         if (child) {
           child.setConnectionsHidden(hidden);
         }
       }
-    } else {
-      connection.setHidden(hidden);
     }
   }
 };

core/connection.js

@@ -666,9 +666,8 @@ Blockly.Connection.prototype.hideAll = function() {
  * @return {!Array.<!Blockly.Block>} List of blocks to render.
  */
 Blockly.Connection.prototype.unhideAll = function() {
-  if (!this.hidden_) {
   this.dbList_[this.type].addConnection_(this);
-  }
+  this.hidden_ = false;
   // All blocks that need unhiding must be unhidden before any rendering takes
   // place, since rendering requires knowing the dimensions of lower blocks.
   // Also, since rendering a block renders all its parents, we only need to