MergeProcess: relocate portage reinstall code

This code goes inside _start since it needs to execute in the parent
process.

1 files changed, 66 insertions, 1 deletions

diff --git a/pym/portage/dbapi/_MergeProcess.py b/pym/portage/dbapi/_MergeProcess.py
index 10d8873ec..43111cb16 100644
--- a/pym/portage/dbapi/_MergeProcess.py
+++ b/pym/portage/dbapi/_MergeProcess.py
@@ -1,14 +1,20 @@
 # Copyright 2010-2011 Gentoo Foundation
 # Distributed under the terms of the GNU General Public License v2
 
+import shutil
 import signal
+import tempfile
 import traceback
 
 import errno
 import fcntl
 import portage
 from portage import os, StringIO, _unicode_decode
+from portage.const import PORTAGE_PACKAGE_ATOM
+from portage.dep import match_from_list
 import portage.elog.messages
+from portage.elog import _preload_elog_modules
+from portage.util import ensure_dirs
 from _emerge.PollConstants import PollConstants
 from _emerge.SpawnProcess import SpawnProcess
 
@@ -23,6 +29,60 @@ class MergeProcess(SpawnProcess):
 		'mydbapi', 'prev_mtimes', '_elog_reader_fd', '_elog_reg_id',
 		'_buf', '_elog_keys')
 
+	def _start(self):
+		self._handle_self_reinstall()
+		super(MergeProcess, self)._start()
+
+	def _handle_self_reinstall(self):
+		"""
+		If portage is reinstalling itself, create temporary
+		copies of PORTAGE_BIN_PATH and PORTAGE_PYM_PATH in order
+		to avoid relying on the new versions which may be
+		incompatible. Register an atexit hook to clean up the
+		temporary directories. Pre-load elog modules here since
+		we won't be able to later if they get unmerged (happens
+		when namespace changes).
+		"""
+
+		settings = self.settings
+		cpv = settings.mycpv
+		reinstall_self = False
+		if self.settings["ROOT"] == "/" and \
+			match_from_list(PORTAGE_PACKAGE_ATOM, [cpv]):
+			inherited = frozenset(self.settings.get('INHERITED', '').split())
+			if not self.vartree.dbapi.cpv_exists(cpv) or \
+				'9999' in cpv or \
+				'git' in inherited or \
+				'git-2' in inherited:
+				reinstall_self = True
+
+		if reinstall_self:
+			# Load lazily referenced portage submodules into memory,
+			# so imports won't fail during portage upgrade/downgrade.
+			_preload_elog_modules(self.settings)
+			portage.proxy.lazyimport._preload_portage_submodules()
+
+			# Make the temp directory inside $PORTAGE_TMPDIR/portage, since
+			# it's common for /tmp and /var/tmp to be mounted with the
+			# "noexec" option (see bug #346899).
+			build_prefix = os.path.join(settings["PORTAGE_TMPDIR"], "portage")
+			ensure_dirs(build_prefix)
+			base_path_tmp = tempfile.mkdtemp(
+				"", "._portage_reinstall_.", build_prefix)
+			portage.process.atexit_register(shutil.rmtree, base_path_tmp)
+			dir_perms = 0o755
+			for subdir in "bin", "pym":
+				var_name = "PORTAGE_%s_PATH" % subdir.upper()
+				var_orig = settings[var_name]
+				var_new = os.path.join(base_path_tmp, subdir)
+				settings[var_name] = var_new
+				settings.backup_changes(var_name)
+				shutil.copytree(var_orig, var_new, symlinks=True)
+				os.chmod(var_new, dir_perms)
+			portage._bin_path = settings['PORTAGE_BIN_PATH']
+			portage._pym_path = settings['PORTAGE_PYM_PATH']
+			os.chmod(base_path_tmp, dir_perms)
+
 	def _elog_output_handler(self, fd, event):
 		output = None
 		if event & PollConstants.POLLIN:
@@ -51,7 +111,6 @@ class MergeProcess(SpawnProcess):
 		dblink.merge().
 		"""
 
-		files = self._files
 		elog_reader_fd, elog_writer_fd = os.pipe()
 		fcntl.fcntl(elog_reader_fd, fcntl.F_SETFL,
 			fcntl.fcntl(elog_reader_fd, fcntl.F_GETFL) | os.O_NONBLOCK)
@@ -69,7 +128,13 @@ class MergeProcess(SpawnProcess):
 			self._elog_reader_fd = elog_reader_fd
 			self._buf = ""
 			self._elog_keys = set()
+
+			# invalidate relevant vardbapi caches
+			if self.vartree.dbapi._categories is not None:
+				self.vartree.dbapi._categories = None
 			self.vartree.dbapi._pkgs_changed = True
+			self.vartree.dbapi._clear_pkg_cache(mylink)
+
 			portage.process.spawned_pids.append(pid)
 			return [pid]