From ee85342c25f910e5abf3002da7d13f2e7ceb5181 Mon Sep 17 00:00:00 2001
From: Vladimir Prus <ghost@cs.msu.su>
Date: Fri, 3 Sep 2004 11:20:51 +0000
Subject: [PATCH] Don't error out when 'PATH', 'Path', or 'path' has empty
 elements.

[SVN r24889]
---
 src/tools/common.jam |  2 +-
 src/util/path.jam    | 16 +++++++++++++++-
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/src/tools/common.jam b/src/tools/common.jam
index 5614d3629..f50087867 100644
--- a/src/tools/common.jam
+++ b/src/tools/common.jam
@@ -166,7 +166,7 @@ rule get-absolute-tool-path ( command )
 # If 'path-last' is specified, path is checked after 'additional-paths'.
 rule find-tool ( name : additional-paths * : path-last ? )
 {
-    local path = [ sequence.transform path.make : [ modules.peek : PATH Path path ] ] ;
+    local path = [ path.programs-path ] ;
     local match = [ path.glob $(path) : $(name) $(name).exe ] ;
     local additional-match = [ path.glob $(additional-paths) : $(name) $(name).exe ] ;              
 
diff --git a/src/util/path.jam b/src/util/path.jam
index eae1a64da..d4bfa39d0 100644
--- a/src/util/path.jam
+++ b/src/util/path.jam
@@ -320,7 +320,21 @@ rule relative-to ( path1 path2 )
     return [ join . $(root_1) $(split2) ] ;
 }
 
-
+# Returns the list of paths which are used by the operating system
+# for looking up programs
+rule programs-path ( )
+{
+    local result ;
+    local raw = [ modules.peek : PATH Path path ] ;
+    for local p in $(raw)
+    {
+        if $(p)
+        {
+            result += [ path.make $(p) ] ;
+        }        
+    }
+    return $(result) ;
+}
 
 rule make-NT ( native )
 {