index: always return at least the root for filter prefixes

[bup.git] / lib / bup / index.py

diff --git a/lib/bup/index.py b/lib/bup/index.py
index 31f6c115ff3dc5a2561c291bef69794df450f2d2..8eabfbbc7bb7fa88353b90abdff113dff7b7e12e 100644 (file)
--- a/lib/bup/index.py
+++ b/lib/bup/index.py
@@ -1,6 +1,9 @@
-import metadata, os, stat, struct, tempfile
+import errno, metadata, os, stat, struct, tempfile
+
 from bup import xstat
-from bup.helpers import *
+from bup.helpers import (add_error, log, merge_iter, mmap_readwrite,
+                         progress, qprogress, resolve_parent, slashappend)
+
 
 EMPTY_SHA = '\0'*20
 FAKE_SHA = '\x01'*20
@@ -174,7 +177,7 @@ class Entry:
                                self.gitmode, self.sha, self.flags,
                                self.children_ofs, self.children_n,
                                self.meta_ofs)
-        except (DeprecationWarning, struct.error), e:
+        except (DeprecationWarning, struct.error) as e:
             log('pack error: %s (%r)\n' % (e, self))
             raise
 
@@ -353,7 +356,7 @@ class Reader:
         f = None
         try:
             f = open(filename, 'r+')
-        except IOError, e:
+        except IOError as e:
             if e.errno == errno.ENOENT:
                 pass
             else:
@@ -403,6 +406,11 @@ class Reader:
     def __iter__(self):
         return self.iter()
 
+    def find(self, name):
+        return next((e for e in self.iter(name, wantrecurse=lambda x : True)
+                     if e.name == name),
+                    None)
+
     def exists(self):
         return self.m
 
@@ -419,11 +427,20 @@ class Reader:
 
     def filter(self, prefixes, wantrecurse=None):
         for (rp, path) in reduce_paths(prefixes):
+            any_entries = False
             for e in self.iter(rp, wantrecurse=wantrecurse):
+                any_entries = True
                 assert(e.name.startswith(rp))
                 name = path + e.name[len(rp):]
                 yield (name, e)
-
+            if not any_entries:
+                # Always return at least the top for each prefix.
+                # Otherwise something like "save x/y" will produce
+                # nothing if x is up to date.
+                pe = self.find(rp)
+                assert(pe)
+                name = path + pe.name[len(rp):]
+                yield (name, pe)
 
 # FIXME: this function isn't very generic, because it splits the filename
 # in an odd way and depends on a terminating '/' to indicate directories.
@@ -443,7 +460,7 @@ class Writer:
         self.count = 0
         self.lastfile = None
         self.filename = None
-        self.filename = filename = realpath(filename)
+        self.filename = filename = resolve_parent(filename)
         self.metastore = metastore
         self.tmax = tmax
         (dir,name) = os.path.split(filename)
@@ -529,14 +546,14 @@ class Writer:
 def reduce_paths(paths):
     xpaths = []
     for p in paths:
-        rp = realpath(p)
+        rp = resolve_parent(p)
         try:
             st = os.lstat(rp)
             if stat.S_ISDIR(st.st_mode):
                 rp = slashappend(rp)
                 p = slashappend(p)
             xpaths.append((rp, p))
-        except OSError, e:
+        except OSError as e:
             add_error('reduce_paths: %s' % e)
     xpaths.sort()