SERVER-28149 cherry-picking the single scons-2.5.1 change

1 files changed, 14 insertions, 12 deletions

diff --git a/src/third_party/scons-2.5.0/scons-local-2.5.0/SCons/Node/__init__.py b/src/third_party/scons-2.5.0/scons-local-2.5.0/SCons/Node/__init__.py
index 3ce481b1f7e..6567489c30a 100644
--- a/src/third_party/scons-2.5.0/scons-local-2.5.0/SCons/Node/__init__.py
+++ b/src/third_party/scons-2.5.0/scons-local-2.5.0/SCons/Node/__init__.py
@@ -41,7 +41,7 @@ be able to depend on any other type of "thing."
 # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
-__revision__ = "src/engine/SCons/Node/__init__.py rel_2.5.0:3543:937e55cd78f7 2016/04/09 11:29:54 bdbaddog"
+__revision__ = "src/engine/SCons/Node/__init__.py rel_2.5.1:3735:9dc6cee5c168 2016/11/03 14:02:02 bdbaddog"
 
 import collections
 import copy
@@ -924,9 +924,9 @@ class Node(object):
         scanner's recursive flag says that we should.
         """
         nodes = [self]
-        seen = {}
-        seen[self] = 1
+        seen = set(nodes)
         dependencies = []
+        path_memo = {}
 
         root_node_scanner = self._get_scanner(env, initial_scanner, None, kw)
 
@@ -934,31 +934,33 @@ class Node(object):
             node = nodes.pop(0)
 
             scanner = node._get_scanner(env, initial_scanner, root_node_scanner, kw)
-                
             if not scanner:
                 continue
 
-            path = path_func(scanner)
+            try:
+                path = path_memo[scanner]
+            except KeyError:
+                path = path_func(scanner)
+                path_memo[scanner] = path
 
             included_deps = [x for x in node.get_found_includes(env, scanner, path) if x not in seen]
             if included_deps:
                 dependencies.extend(included_deps)
-                for dep in included_deps:
-                    seen[dep] = 1
+                seen.update(included_deps)
                 nodes.extend(scanner.recurse_nodes(included_deps))
 
         return dependencies
 
     def _get_scanner(self, env, initial_scanner, root_node_scanner, kw):
-        if not initial_scanner:
+        if initial_scanner:
+            # handle explicit scanner case
+            scanner = initial_scanner.select(self)
+        else:
             # handle implicit scanner case
             scanner = self.get_env_scanner(env, kw)
             if scanner:
                 scanner = scanner.select(self)
-        else:
-            # handle explicit scanner case
-            scanner = initial_scanner.select(self)
-            
+
         if not scanner:
             # no scanner could be found for the given node's scanner key;
             # thus, make an attempt at using a default.