bitbake: Refactor the environment variable handling

Refactor the environment variable handling so that it more closes matches the
changes that have been made in bitbake-dev.

git-svn-id: https://svn.o-hand.com/repos/poky/trunk@5527 311d38ba-8fff-0310-9ca6-ca027cbcb966

bitbake/bin/bitbake

@@ -113,15 +113,9 @@ Default BBFILES are the .bb files in the current directory.""" )
 
     cooker = bb.cooker.BBCooker(configuration)
 
-    # Optionally clean up the environment
-    if 'BB_PRESERVE_ENV' not in os.environ:
-        if 'BB_ENV_WHITELIST' in os.environ:
-            good_vars = os.environ['BB_ENV_WHITELIST'].split()
-        else:
-            good_vars = bb.utils.preserved_envvars_list()
-        if 'BB_ENV_EXTRAWHITE' in os.environ:
-            good_vars.extend(os.environ['BB_ENV_EXTRAWHITE'].split())
-        bb.utils.filter_environment(good_vars)
+    # Clear away any spurious environment variables. But don't wipe the
+    # environment totally.
+    bb.utils.clean_environment()
 
     cooker.parseConfiguration()