lib/nanoc/base/result_data/item_rep.rb in nanoc-3.7.5 vs lib/nanoc/base/result_data/item_rep.rb in nanoc-3.8.0

@@ -233,24 +233,33 @@
       # Notify
       Nanoc::NotificationCenter.post(:visit_started, item)
       Nanoc::NotificationCenter.post(:visit_ended,   item)
 
       # Get name of last pre-layout snapshot
-      snapshot = params.fetch(:snapshot) { @content[:pre] ? :pre : :last }
-      is_moving = [:pre, :post, :last].include?(snapshot)
+      snapshot_name = params.fetch(:snapshot) { @content[:pre] ? :pre : :last }
+      is_moving = [:pre, :post, :last].include?(snapshot_name)
 
       # Check existance of snapshot
-      if !is_moving && snapshots.find { |s| s.first == snapshot && s.last == true }.nil?
-        raise Nanoc::Errors::NoSuchSnapshot.new(self, snapshot)
+      snapshot = snapshots.find { |s| s.first == snapshot_name }
+      if !is_moving && (snapshot.nil? || snapshot[-1] == false)
+        raise Nanoc::Errors::NoSuchSnapshot.new(self, snapshot_name)
       end
 
-      # Require compilation
-      if @content[snapshot].nil? || (!self.compiled? && is_moving)
+      # Verify snapshot is usable
+      is_still_moving =
+        case snapshot_name
+        when :post, :last
+          true
+        when :pre
+          snapshot.nil? || !snapshot[-1]
+        end
+      is_usable_snapshot = @content[snapshot_name] && (self.compiled? || !is_still_moving)
+      unless is_usable_snapshot
         raise Nanoc::Errors::UnmetDependency.new(self)
-      else
-        @content[snapshot]
       end
+
+      @content[snapshot_name]
     end
 
     # Checks whether content exists at a given snapshot.
     #
     # @return [Boolean] True if content exists for the snapshot with the
@@ -414,11 +423,19 @@
     #   the snapshot will be updated; false if it is a non-final moving
     #   snapshot (such as `:pre`, `:post` or `:last`)
     #
     # @return [void]
     def snapshot(snapshot_name, params = {})
-      is_final = params.fetch(:final) { true }
-      @content[snapshot_name] = @content[:last] unless self.binary?
+      is_final = params.fetch(:final, true)
+
+      unless self.binary?
+        @content[snapshot_name] = @content[:last]
+      end
+
+      if snapshot_name == :pre && is_final
+        snapshots << [:pre, true]
+      end
+
       write(snapshot_name) if is_final
     end
 
     # Returns a recording proxy that is used for determining whether the
     # compilation has changed, and thus whether the item rep needs to be