Made Boost Build ignore any received empty command-line arguments that it previously interpreted as targets. This was causing Boost Build test failures (rule path.make-UNIX called with an empty parameter) on many non-Windows platforms where empty parameters are not automatically stripped by the OS or the used Python process call implementation.

[SVN r78902]

v2/build/build-request.jam

@@ -153,7 +153,7 @@ rule from-command-line ( command-line * )
                 properties += [ convert-command-line-element $(e) :
                     $(feature-space) ] ;
             }
-            else
+            else if $(e)
             {
                 targets += $(e) ;
             }

v2/build/build_request.py

@@ -114,7 +114,7 @@ def from_command_line(command_line):
             # consists of implicit feature values.
             if e.find("=") != -1 or looks_like_implicit_value(e.split("/")[0]):                
                 properties += convert_command_line_element(e)
-            else:
+            else if e:
                 targets.append(e)
 
     return [targets, properties]