Merged r11827 to r11833 from trunk (#14015).

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/branches/2.3-stable@11996 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/models/issue.rb

@@ -854,18 +854,99 @@ class Issue < ActiveRecord::Base
   end
 
   # Returns all the other issues that depend on the issue
+  # The algorithm is a modified breadth first search (bfs)
   def all_dependent_issues(except=[])
-    except << self
+    # The found dependencies
     dependencies = []
-    dependencies += relations_from.map(&:issue_to)
-    dependencies += children unless leaf?
-    dependencies.compact!
+
+    # The visited flag for every node (issue) used by the breadth first search
+    eNOT_DISCOVERED         = 0       # The issue is "new" to the algorithm, it has not seen it before.
+
+    ePROCESS_ALL            = 1       # The issue is added to the queue. Process both children and relations of
+                                      # the issue when it is processed.
+
+    ePROCESS_RELATIONS_ONLY = 2       # The issue was added to the queue and will be output as dependent issue,
+                                      # but its children will not be added to the queue when it is processed.
+
+    eRELATIONS_PROCESSED    = 3       # The related issues, the parent issue and the issue itself have been added to
+                                      # the queue, but its children have not been added.
+
+    ePROCESS_CHILDREN_ONLY  = 4       # The relations and the parent of the issue have been added to the queue, but
+                                      # the children still need to be processed.
+
+    eALL_PROCESSED          = 5       # The issue and all its children, its parent and its related issues have been
+                                      # added as dependent issues. It needs no further processing.
+
+    issue_status = Hash.new(eNOT_DISCOVERED)
+
+    # The queue
+    queue = []
+
+    # Initialize the bfs, add start node (self) to the queue
+    queue << self
+    issue_status[self] = ePROCESS_ALL
+
+    while (!queue.empty?) do
+      current_issue = queue.shift
+      current_issue_status = issue_status[current_issue]
+      dependencies << current_issue
+
+      # Add parent to queue, if not already in it.
+      parent = current_issue.parent
+      parent_status = issue_status[parent]
+
+      if parent && (parent_status == eNOT_DISCOVERED) && !except.include?(parent)
+        queue << parent
+        issue_status[parent] = ePROCESS_RELATIONS_ONLY
+      end
+
+      # Add children to queue, but only if they are not already in it and
+      # the children of the current node need to be processed.
+      if (current_issue_status == ePROCESS_CHILDREN_ONLY || current_issue_status == ePROCESS_ALL)
+        current_issue.children.each do |child|
+          next if except.include?(child)
+
+          if (issue_status[child] == eNOT_DISCOVERED)
+            queue << child
+            issue_status[child] = ePROCESS_ALL
+          elsif (issue_status[child] == eRELATIONS_PROCESSED)
+            queue << child
+            issue_status[child] = ePROCESS_CHILDREN_ONLY
+          elsif (issue_status[child] == ePROCESS_RELATIONS_ONLY)
+            queue << child
+            issue_status[child] = ePROCESS_ALL
+          end
+        end
+      end
+
+      # Add related issues to the queue, if they are not already in it.
+      current_issue.relations_from.map(&:issue_to).each do |related_issue|
+        next if except.include?(related_issue)
+
+        if (issue_status[related_issue] == eNOT_DISCOVERED)
+          queue << related_issue
+          issue_status[related_issue] = ePROCESS_ALL
+        elsif (issue_status[related_issue] == eRELATIONS_PROCESSED)
+          queue << related_issue
+          issue_status[related_issue] = ePROCESS_CHILDREN_ONLY
+        elsif (issue_status[related_issue] == ePROCESS_RELATIONS_ONLY)
+          queue << related_issue
+          issue_status[related_issue] = ePROCESS_ALL
+        end
+      end
+
+      # Set new status for current issue
+      if (current_issue_status == ePROCESS_ALL) || (current_issue_status == ePROCESS_CHILDREN_ONLY)
+        issue_status[current_issue] = eALL_PROCESSED
+      elsif (current_issue_status == ePROCESS_RELATIONS_ONLY)
+        issue_status[current_issue] = eRELATIONS_PROCESSED
+      end
+    end # while
+
+    # Remove the issues from the "except" parameter from the result array
     dependencies -= except
-    dependencies += dependencies.map {|issue| issue.all_dependent_issues(except)}.flatten
-    if parent
-      dependencies << parent
-      dependencies += parent.all_dependent_issues(except + parent.descendants)
-    end
+    dependencies.delete(self)
+
     dependencies
   end