[gentoo-portage-dev] [PATCH] fs_template.gen_label: handle hash randomization

[Zac Medico]

With python 3.3 and later, hash randomization causes __hash__() results
to vary randomly for each run. Fix gen_label to use a md5 digest which
gives consistent results for all runs. Maintain backward compatible
behavior for older python when hash randomization is disabled. This
fixes the anydbm module so that its database file name will be
consistent for all runs (no randomization).
---
 pym/portage/cache/fs_template.py | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/pym/portage/cache/fs_template.py b/pym/portage/cache/fs_template.py
index fa44abc..05dfaab 100644
--- a/pym/portage/cache/fs_template.py
+++ b/pym/portage/cache/fs_template.py
@@ -5,10 +5,11 @@
 import os as _os
 import sys
 from portage.cache import template
-from portage import os
+from portage import os, _unicode_encode
 
 from portage.proxy.lazyimport import lazyimport
 lazyimport(globals(),
+	'portage:checksum',
 	'portage.exception:PortageException',
 	'portage.util:apply_permissions,ensure_dirs',
 )
@@ -89,5 +90,12 @@ def gen_label(base, label):
 	label = label.strip("\"").strip("'")
 	label = os.path.join(*(label.rstrip(os.path.sep).split(os.path.sep)))
 	tail = os.path.split(label)[1]
-	return "%s-%X" % (tail, abs(label.__hash__()))
+	if sys.hexversion >= 0x3030000 or os.environ.get("PYTHONHASHSEED") == "random":
+		# Hash randomization makes __hash__() random, so don't use it.
+		hexdigest = checksum._new_md5(_unicode_encode(label)).hexdigest()
+	else:
+		# backward compat
+		hexdigest = "%X" % abs(label.__hash__())
+
+	return "%s-%s" % (tail, hexdigest)
 
-- 
2.4.10