Similar to the sys-apps/portage protection, also add protection against

inappropriately uninstalling either app-shells/bash or dev-lang/python.
(trunk r10171)

svn path=/main/branches/2.1.2/; revision=10172

diff --git a/bin/emerge b/bin/emerge
index 75da6349cfc90b96e1c3b5127e15b224635891da..808101b9c280440dd3f444761222fe7c0d84ca1a 100755 (executable)
--- a/bin/emerge
+++ b/bin/emerge
@@ -3640,6 +3640,9 @@ class depgraph(object):
                                node.operation != "uninstall"]
 
                # sys-apps/portage needs special treatment if ROOT="/"
+               portage_python_dep = ">=dev-lang/python-2.4"
+               portage_unslotted_deps = frozenset(
+                       ["app-shells/bash", "sys-apps/portage"])
                portage_node = self.mydbapi["/"].match_pkgs("sys-apps/portage")
                if portage_node:
                        portage_node = portage_node[0]
@@ -3828,10 +3831,28 @@ class depgraph(object):
                                                continue
 
                                        if "/" == task.root:
-                                               # Never uninstall sys-apps/portage
-                                               # except through replacement.
-                                               if "sys-apps/portage" == task.cp:
+                                               # Never uninstall sys-apps/portage or it's essential
+                                               # dependencies, except through replacement.
+                                               if task.cp in portage_unslotted_deps:
                                                        continue
+
+                                               # Don't uninstall python if it appears to be
+                                               # the only suitable one installed.
+                                               if task.cp == "dev-lang/python" and \
+                                                       portage.match_from_list(
+                                                       portage_python_dep, [task.cpv_slot]):
+                                                       vardb = root_config.trees["vartree"].dbapi
+                                                       other_version = None
+                                                       for pkg in vardb.match_pkgs(portage_python_dep):
+                                                               if pkg.cpv == task.cpv and \
+                                                                       pkg.metadata["COUNTER"] == \
+                                                                       task.metadata["COUNTER"]:
+                                                                       continue
+                                                               other_version = pkg
+                                                               break
+                                                       if other_version is None:
+                                                               continue
+
                                                # For packages in the system set, don't take
                                                # any chances. If the conflict can't be resolved
                                                # by a normal replacement operation then abort.