From fabb58e0eaa6e48ec389c41019ee1a65d2d1685e Mon Sep 17 00:00:00 2001
From: David Capello <davidcapello@gmail.com>
Date: Sun, 16 Mar 2014 21:56:18 -0300
Subject: [PATCH] Fix crash in "go to" commands, don't access to null layer

---
 src/app/commands/cmd_goto_layer.cpp | 39 ++++++++++++++++++-----------
 1 file changed, 25 insertions(+), 14 deletions(-)

diff --git a/src/app/commands/cmd_goto_layer.cpp b/src/app/commands/cmd_goto_layer.cpp
index 77ad3b550..b5af2b4c1 100644
--- a/src/app/commands/cmd_goto_layer.cpp
+++ b/src/app/commands/cmd_goto_layer.cpp
@@ -32,7 +32,22 @@
 
 namespace app {
 
-class GotoPreviousLayerCommand : public Command {
+class GotoCommand : public Command {
+public:
+  GotoCommand(const char* short_name, const char* friendly_name, CommandFlags flags)
+    : Command(short_name, friendly_name, flags) {
+  }
+
+protected:
+  void updateStatusBar(DocumentLocation& location) {
+    if (location.layer() != NULL)
+      StatusBar::instance()
+        ->setStatusText(1000, "Layer `%s' selected",
+          location.layer()->getName().c_str());
+  }
+};
+
+class GotoPreviousLayerCommand : public GotoCommand {
 public:
   GotoPreviousLayerCommand();
   Command* clone() { return new GotoPreviousLayerCommand(*this); }
@@ -43,9 +58,9 @@ protected:
 };
 
 GotoPreviousLayerCommand::GotoPreviousLayerCommand()
-  : Command("GotoPreviousLayer",
-            "Goto Previous Layer",
-            CmdUIOnlyFlag)
+ : GotoCommand("GotoPreviousLayer",
+               "Goto Previous Layer",
+               CmdUIOnlyFlag)
 {
 }
 
@@ -71,12 +86,10 @@ void GotoPreviousLayerCommand::onExecute(Context* context)
   current_editor->setLayer(location.layer());
   current_editor->flashCurrentLayer();
 
-  StatusBar::instance()
-    ->setStatusText(1000, "Layer `%s' selected",
-                    location.layer()->getName().c_str());
+  updateStatusBar(location);
 }
 
-class GotoNextLayerCommand : public Command {
+class GotoNextLayerCommand : public GotoCommand {
 public:
   GotoNextLayerCommand();
   Command* clone() { return new GotoNextLayerCommand(*this); }
@@ -87,9 +100,9 @@ protected:
 };
 
 GotoNextLayerCommand::GotoNextLayerCommand()
-  : Command("GotoNextLayer",
-            "Goto Next Layer",
-            CmdUIOnlyFlag)
+  : GotoCommand("GotoNextLayer",
+                "Goto Next Layer",
+                CmdUIOnlyFlag)
 {
 }
 
@@ -115,9 +128,7 @@ void GotoNextLayerCommand::onExecute(Context* context)
   current_editor->setLayer(location.layer());
   current_editor->flashCurrentLayer();
 
-  StatusBar::instance()
-    ->setStatusText(1000, "Layer `%s' selected",
-                    location.layer()->getName().c_str());
+  updateStatusBar(location);
 }
 
 Command* CommandFactory::createGotoPreviousLayerCommand()