terraform: don't panic if no state in Walk return [GH-403]

CHANGELOG.md

@@ -1,6 +1,9 @@
 ## 0.3.1 (unreleased)
 
+BUG FIXES:
 
+  * core: Remove panic case when applying with a plan that generates no
+      new state. [GH-403]
 
 ## 0.3.0 (October 14, 2014)
 

terraform/context.go

@@ -517,13 +517,13 @@ func (c *walkContext) Walk() error {
 	// Likewise, if we have no resources in our state, we're done. This
 	// guards against the case that we destroyed.
 	mod := c.Context.state.ModuleByPath(c.Path)
+	if mod == nil {
+		return nil
+	}
 	if c.Operation == walkApply {
 		// On Apply, we prune so that we don't do outputs if we destroyed
 		mod.prune()
 	}
-	if mod == nil || len(mod.Resources) == 0 {
-		return nil
-	}
 	if len(mod.Resources) == 0 {
 		mod.Outputs = nil
 		return nil