Add portage.const.EPREFIX, for prefix installs.

The EPREFIX for the current install is hardcoded here, but access to
this constant should be minimal, in favor of access via the EPREFIX
setting of a config instance (since it's possible to contruct a config
instance with a different EPREFIX).

diff --git a/pym/portage/const.py b/pym/portage/const.py
index 3dad36a2efea41eb1f8e67676c55ffbd174c4b8a..5eeebe1308c2715aeb7537d5e22d027a5463aac8 100644 (file)
--- a/pym/portage/const.py
+++ b/pym/portage/const.py
@@ -140,6 +140,24 @@ MANIFEST2_HASH_DEFAULTS = frozenset(["SHA1", "SHA256", "RMD160"])
 MANIFEST2_REQUIRED_HASH  = "SHA256"
 
 MANIFEST2_IDENTIFIERS    = ("AUX", "MISC", "DIST", "EBUILD")
+
+# The EPREFIX for the current install is hardcoded here, but access to this
+# constant should be minimal, in favor of access via the EPREFIX setting of
+# a config instance (since it's possible to contruct a config instance with
+# a different EPREFIX). Therefore, the EPREFIX constant should *NOT* be used
+# in the definition of any other contstants within this file.
+EPREFIX=""
+
+# pick up EPREFIX from the environment if set
+if "__PORTAGE_TEST_EPREFIX" in os.environ:
+       EPREFIX = os.environ["__PORTAGE_TEST_EPREFIX"]
+       if EPREFIX:
+               EPREFIX = os.path.normpath(EPREFIX)
+
+elif EPREFIX:
+       # Propagate the constant to other portage code which uses this variable.
+       os.environ["__PORTAGE_TEST_EPREFIX"] = EPREFIX
+
 # ===========================================================================
 # END OF CONSTANTS -- END OF CONSTANTS -- END OF CONSTANTS -- END OF CONSTANT
 # ===========================================================================