merge-sync: handle unmerge corner cases

In dblink_merged_path we need to distinguish between existing and
non-existing, since we need an existing path of syncfs.

diff --git a/pym/portage/dbapi/vartree.py b/pym/portage/dbapi/vartree.py
index 5bcd07797758f0f1d88cf60aeaf5477dd54a696b..aae23e6bac3ae8a3eb3473f0a3cffbf4720846c3 100644 (file)
--- a/pym/portage/dbapi/vartree.py
+++ b/pym/portage/dbapi/vartree.py
@@ -2156,7 +2156,7 @@ class dblink(object):
                                        # here so that _unmerge_dirs can see that we've
                                        # removed a file from this device, and will record
                                        # the parent directory for a syncfs call.
-                                       self._merged_path(file_name, lstatobj)
+                                       self._merged_path(file_name, lstatobj, exists=False)
 
                                finally:
                                        if bsd_chflags and pflags != 0:
@@ -4706,10 +4706,17 @@ class dblink(object):
                                        outfile.write("dev %s\n" % myrealdest)
                                showMessage(zing + " " + mydest + "\n")
 
-       def _merged_path(self, path, lstatobj):
+       def _merged_path(self, path, lstatobj, exists=True):
                previous_path = self._device_path_map.get(lstatobj.st_dev)
-               if previous_path is None or len(path) < len(previous_path):
-                       self._device_path_map[lstatobj.st_dev] = path
+               if previous_path is None or previous_path is False or \
+                       (exists and len(path) < len(previous_path)):
+                       if exists:
+                               self._device_path_map[lstatobj.st_dev] = path
+                       else:
+                               # This entry is used to indicate that we've unmerged
+                               # a file from this device, and later, this entry is
+                               # replaced by a parent directory.
+                               self._device_path_map[lstatobj.st_dev] = False
 
        def _post_merge_sync(self):
                """
@@ -4731,6 +4738,8 @@ class dblink(object):
                                proc.wait()
                else:
                        for path in self._device_path_map.values():
+                               if path is False:
+                                       continue
                                try:
                                        fd = os.open(path, os.O_RDONLY)
                                except OSError: