From c357ca66340ca7ec81f6cac584b006e543847ed7 Mon Sep 17 00:00:00 2001
From: Jon-Paul Sullivan <jonpaul.sullivan@hp.com>
Date: Mon, 7 Apr 2014 17:59:33 +0100
Subject: [PATCH] Iterate over provided elements first

To ensure that we have the list of provided elements from the
command line before looking up dependencies, use a deque and
popleft() to take the elements on a first-in/first-out basis.

Change-Id: I0a2c21fa081763fd3cc8358be25dafeee1ed4718
Closes-Bug: #1303911
---
 diskimage_builder/element_dependencies.py   |  7 +++++--
 diskimage_builder/tests/test_elementdeps.py | 19 +++++++++++++++++--
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/diskimage_builder/element_dependencies.py b/diskimage_builder/element_dependencies.py
index 76c63a86e..e404a92f2 100644
--- a/diskimage_builder/element_dependencies.py
+++ b/diskimage_builder/element_dependencies.py
@@ -14,6 +14,7 @@
 # under the License.
 
 import argparse
+import collections
 import os
 import sys
 
@@ -84,11 +85,13 @@ def expand_dependencies(user_elements, elements_dir=None):
              including any transitive dependencies.
     """
     final_elements = set(user_elements)
-    check_queue = list(user_elements)
+    check_queue = collections.deque(user_elements)
     provided = set()
 
     while check_queue:
-        element = check_queue.pop()
+        # bug #1303911 - run through the provided elements first to avoid
+        # adding unwanted dependencies and looking for virtual elements
+        element = check_queue.popleft()
         if element in provided:
             continue
         deps = dependencies(element, elements_dir)
diff --git a/diskimage_builder/tests/test_elementdeps.py b/diskimage_builder/tests/test_elementdeps.py
index 0c945d291..4700474e3 100644
--- a/diskimage_builder/tests/test_elementdeps.py
+++ b/diskimage_builder/tests/test_elementdeps.py
@@ -51,9 +51,17 @@ class TestElementDeps(testtools.TestCase):
                           [],
                           ['virtual'])
         _populate_element(self.element_dir, 'requires_virtual', ['virtual'])
-        _populate_element(self.element_dir, 'virtual', [])
+        _populate_element(self.element_dir, 'virtual', ['extra_dependency'])
+        _populate_element(self.element_dir, 'extra_dependency', [])
         _populate_element(self.element_dir, 'circular1', ['circular2'])
         _populate_element(self.element_dir, 'circular2', ['circular1'])
+        _populate_element(self.element_dir,
+                          'provides_new_virtual',
+                          [],
+                          ['new_virtual'])
+        _populate_element(self.element_dir,
+                          'requires_new_virtual',
+                          ['new_virtual'])
 
     def test_non_transitive_deps(self):
         result = element_dependencies.expand_dependencies(
@@ -90,7 +98,7 @@ class TestElementDeps(testtools.TestCase):
 
     def test_provide(self):
         result = element_dependencies.expand_dependencies(
-            ['requires_virtual', 'provides_virtual'],
+            ['provides_virtual', 'requires_virtual'],
             elements_dir=self.element_dir)
         self.assertEqual(set(['requires_virtual', 'provides_virtual']), result)
 
@@ -100,6 +108,13 @@ class TestElementDeps(testtools.TestCase):
                           ['virtual', 'provides_virtual'],
                           self.element_dir)
 
+    def test_provide_virtual_ordering(self):
+        result = element_dependencies.expand_dependencies(
+            ['requires_new_virtual', 'provides_new_virtual'],
+            elements_dir=self.element_dir)
+        self.assertEqual(set(['requires_new_virtual', 'provides_new_virtual']),
+                         result)
+
 
 class TestElements(testtools.TestCase):
     def test_depends_on_env(self):