From 094418f92868a4f0bcd8925e079e230329ffaa5d Mon Sep 17 00:00:00 2001
From: alschmiedt <aschmiedt@google.com>
Date: Thu, 13 Dec 2018 08:11:16 -0800
Subject: [PATCH 1/2] Reconnects child blocks when an undo is done on an else
 block

---
 blocks/logic.js | 50 +++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 44 insertions(+), 6 deletions(-)

diff --git a/blocks/logic.js b/blocks/logic.js
index 01f4e55b6..f115224bd 100644
--- a/blocks/logic.js
+++ b/blocks/logic.js
@@ -331,7 +331,7 @@ Blockly.Constants.Logic.CONTROLS_IF_MUTATOR_MIXIN = {
   domToMutation: function(xmlElement) {
     this.elseifCount_ = parseInt(xmlElement.getAttribute('elseif'), 10) || 0;
     this.elseCount_ = parseInt(xmlElement.getAttribute('else'), 10) || 0;
-    this.updateShape_();
+    this.rebuildShape_();
   },
   /**
    * Populate the mutator's dialog with this block's components.
@@ -388,11 +388,8 @@ Blockly.Constants.Logic.CONTROLS_IF_MUTATOR_MIXIN = {
     }
     this.updateShape_();
     // Reconnect any child blocks.
-    for (var i = 1; i <= this.elseifCount_; i++) {
-      Blockly.Mutator.reconnect(valueConnections[i], this, 'IF' + i);
-      Blockly.Mutator.reconnect(statementConnections[i], this, 'DO' + i);
-    }
-    Blockly.Mutator.reconnect(elseStatementConnection, this, 'ELSE');
+    this.reconnectChildBlocks_(valueConnections, statementConnections,
+        elseStatementConnection);
   },
   /**
    * Store pointers to any connected child blocks.
@@ -425,6 +422,30 @@ Blockly.Constants.Logic.CONTROLS_IF_MUTATOR_MIXIN = {
           clauseBlock.nextConnection.targetBlock();
     }
   },
+  /**
+   * Reconstructs the block with all child blocks attached.
+   * Fixes issue #2037.
+   */
+  rebuildShape_: function() {
+    var valueConnections = [null];
+    var statementConnections = [null];
+    var elseStatementConnection = null;
+
+    if (this.getInput('ELSE')) {
+      elseStatementConnection = this.getInput('ELSE').connection.targetConnection;
+    }
+    var i = 1;
+    while (this.getInput('IF' + i)) {
+      var inputIf = this.getInput('IF' + i);
+      var inputDo = this.getInput('DO' + i);
+      valueConnections.push(inputIf.connection.targetConnection);
+      statementConnections.push(inputDo.connection.targetConnection);
+      i++;
+    }
+    this.updateShape_();
+    this.reconnectChildBlocks_(valueConnections, statementConnections,
+        elseStatementConnection);
+  },
   /**
    * Modify this block to have the correct number of inputs.
    * @this Blockly.Block
@@ -453,6 +474,23 @@ Blockly.Constants.Logic.CONTROLS_IF_MUTATOR_MIXIN = {
       this.appendStatementInput('ELSE')
           .appendField(Blockly.Msg['CONTROLS_IF_MSG_ELSE']);
     }
+  },
+  /**
+   * Reconnects child blocks.
+   * @param {!Array<?Blockly.RenderedConnection>} valueConnections List of value
+   * connectsions for if input.
+   * @param {!Array<?Blockly.RenderedConnection>} statementConnections List of
+   * statement connections for do input.
+   * @param {?Blockly.RenderedConnection} elseStatementConnection Statement
+   * connection for else input.
+   */
+  reconnectChildBlocks_: function(valueConnections, statementConnections,
+      elseStatementConnection) {
+    for (var i = 1; i <= this.elseifCount_; i++) {
+      Blockly.Mutator.reconnect(valueConnections[i], this, 'IF' + i);
+      Blockly.Mutator.reconnect(statementConnections[i], this, 'DO' + i);
+    }
+    Blockly.Mutator.reconnect(elseStatementConnection, this, 'ELSE');
   }
 };
 

From 3bf933720597b55c69edb83d739733f101869988 Mon Sep 17 00:00:00 2001
From: alschmiedt <aschmiedt@google.com>
Date: Thu, 13 Dec 2018 10:32:38 -0800
Subject: [PATCH 2/2] Fixed comment

---
 blocks/logic.js | 1 -
 1 file changed, 1 deletion(-)

diff --git a/blocks/logic.js b/blocks/logic.js
index f115224bd..e904085c6 100644
--- a/blocks/logic.js
+++ b/blocks/logic.js
@@ -424,7 +424,6 @@ Blockly.Constants.Logic.CONTROLS_IF_MUTATOR_MIXIN = {
   },
   /**
    * Reconstructs the block with all child blocks attached.
-   * Fixes issue #2037.
    */
   rebuildShape_: function() {
     var valueConnections = [null];