diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/GerritResources.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/GerritResources.java
index d106ad5c4d..c45c797735 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/GerritResources.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/GerritResources.java
@@ -37,6 +37,9 @@ public interface GerritResources extends ClientBundle {
   @Source("editText.png")
   public ImageResource edit();
 
+  @Source("mediaFloppy.png")
+  public ImageResource save();
+
   @Source("starOpen.gif")
   public ImageResource starOpen();
 
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/PatchSetSelectBox2.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/PatchSetSelectBox2.java
index d3fce02a44..786df47ecd 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/PatchSetSelectBox2.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/PatchSetSelectBox2.java
@@ -16,8 +16,8 @@ package com.google.gerrit.client.diff;
 
 import com.google.gerrit.client.Dispatcher;
 import com.google.gerrit.client.Gerrit;
+import com.google.gerrit.client.VoidResult;
 import com.google.gerrit.client.WebLinkInfo;
-import com.google.gerrit.client.change.EditFileAction;
 import com.google.gerrit.client.changes.ChangeFileApi;
 import com.google.gerrit.client.changes.ChangeInfo.RevisionInfo;
 import com.google.gerrit.client.patches.PatchUtil;
@@ -139,21 +139,35 @@ class PatchSetSelectBox2 extends Composite {
   }
 
   private Widget createEditIcon() {
-    Anchor anchor = new Anchor(
+    final Anchor anchor = new Anchor(
         new ImageResourceRenderer().render(Gerrit.RESOURCES.edit()));
     anchor.addClickHandler(new ClickHandler() {
+      boolean editing = false;
       @Override
       public void onClick(ClickEvent event) {
         final PatchSet.Id id = (idActive == null) ? other.idActive : idActive;
-        ChangeFileApi.getContent(id, path,
-            new GerritCallback<String>() {
-              @Override
-              public void onSuccess(String result) {
-                EditFileAction edit = new EditFileAction(
-                    id, result, path, style.replyBox(), null, icon);
-                edit.onEdit();
-              }
-            });
+        editing = !editing;
+        parent.editSideB(editing);
+
+        if (editing) {
+          ChangeFileApi.getContent(id, path,
+              new GerritCallback<String>() {
+            @Override
+            public void onSuccess(String content) {
+              parent.setSideBContent(content);
+            }
+          });
+          anchor.setHTML(new ImageResourceRenderer().render(Gerrit.RESOURCES.save()));
+        } else {
+          anchor.setHTML(new ImageResourceRenderer().render(Gerrit.RESOURCES.edit()));
+          String siteBContent = parent.getSideBContent();
+          ChangeFileApi.putContent(id, path, siteBContent,
+              new GerritCallback<VoidResult>() {
+                @Override
+                public void onSuccess(VoidResult result) {
+                }
+              });
+        }
       }
     });
     anchor.setTitle(PatchUtil.C.edit());
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/SideBySide2.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/SideBySide2.java
index 641f5a64a9..2547a4f106 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/SideBySide2.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/SideBySide2.java
@@ -132,6 +132,8 @@ public class SideBySide2 extends Screen {
   private List<HandlerRegistration> handlers;
   private PreferencesAction prefsAction;
   private int reloadVersionId;
+  private KeyMap sbsKeyMap;
+  private boolean isEdited = false;
 
   public SideBySide2(
       PatchSet.Id base,
@@ -338,7 +340,7 @@ public class SideBySide2 extends Screen {
     cm.on("cursorActivity", updateActiveLine(cm));
     cm.on("gutterClick", onGutterClick(cm));
     cm.on("focus", updateActiveLine(cm));
-    cm.addKeyMap(KeyMap.create()
+    sbsKeyMap = KeyMap.create()
         .on("A", upToChange(true))
         .on("U", upToChange(false))
         .on("[", header.navigate(Direction.PREV))
@@ -403,7 +405,8 @@ public class SideBySide2 extends Screen {
           public void run() {
             cm.execCommand("selectAll");
           }
-        }));
+        });
+    cm.addKeyMap(sbsKeyMap);
     if (prefs.renderEntireFile()) {
       cm.addKeyMap(RENDER_ENTIRE_FILE_KEYMAP);
     }
@@ -415,6 +418,9 @@ public class SideBySide2 extends Screen {
 
       @Override
       public void handle(CodeMirror cm, LineCharacter anchor, LineCharacter head) {
+        if (isEdited) {
+          return;
+        }
         if (anchor == head
             || (anchor.getLine() == head.getLine()
              && anchor.getCh() == head.getCh())) {
@@ -533,6 +539,30 @@ public class SideBySide2 extends Screen {
     }));
   }
 
+  public void editSideB(boolean state) {
+    isEdited = state;
+    cmB.setOption("readOnly", !state);
+    JumpKeys.enable(!state);
+    if (state) {
+      removeKeyHandlerRegistrations();
+      cmB.removeKeyMap(sbsKeyMap);
+      cmB.setOption("keyMap", "default");
+      cmB.focus();
+    } else {
+      cmB.setOption("keyMap", "vim_ro");
+      cmB.addKeyMap(sbsKeyMap);
+      registerKeys();
+    }
+  }
+
+  public String getSideBContent() {
+    return cmB.getValue();
+  }
+
+  public void setSideBContent(String content) {
+    cmB.setValue(content);
+  }
+
   private void display(final CommentsCollections comments) {
     setThemeStyles(prefs.theme().isDark());
     setShowTabs(prefs.showTabs());
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/mediaFloppy.png b/gerrit-gwtui/src/main/java/com/google/gerrit/client/mediaFloppy.png
new file mode 100644
index 0000000000..f1d7a19859
Binary files /dev/null and b/gerrit-gwtui/src/main/java/com/google/gerrit/client/mediaFloppy.png differ
diff --git a/gerrit-gwtui/src/main/java/net/codemirror/lib/CodeMirror.java b/gerrit-gwtui/src/main/java/net/codemirror/lib/CodeMirror.java
index 941ef7a30b..4b8970a14b 100644
--- a/gerrit-gwtui/src/main/java/net/codemirror/lib/CodeMirror.java
+++ b/gerrit-gwtui/src/main/java/net/codemirror/lib/CodeMirror.java
@@ -96,7 +96,15 @@ public class CodeMirror extends JavaScriptObject {
 
   private final native void addLineClassNative(LineHandle line, String where,
       String lineClass) /*-{
-    this.addLineClass(line, where, lineClass);
+    try {
+      this.addLineClass(line, where, lineClass);
+    } catch (err) {
+      if ("TypeError: Cannot read property 'parrent' of undefinded" == err.toString()) {
+        // ignore CodeMirror bug after going to new line
+        return;
+      }
+      throw err;
+    }
   }-*/;
 
   public final void removeLineClass(int line, LineClassWhere where,
@@ -362,4 +370,8 @@ public class CodeMirror extends JavaScriptObject {
   public interface BeforeSelectionChangeHandler {
     public void handle(CodeMirror instance, LineCharacter anchor, LineCharacter head);
   }
+
+  public final native String getValue() /*-{
+    return this.getValue();
+  }-*/;
 }