Fix file restore, add xattr value change test

The single file restore test had a bug, in that it was depending on
various test steps to execute fast enough that the wall clock did not
advance to the next second. This has been fixed by allowing manifests
to be done on single files instead of just directories.

Add a test for an extended attribute value changing, and that being
the only change in the live data. The backup needs to notice that it
has changed. This was intended to be the original change in this
commit, but I ran into the test bug above, so I had to fix that too.
I was too lazy to detangle the two sets of changes for commits.

7 files changed, 56 insertions, 31 deletions

diff --git a/yarns/0030-basics.yarn b/yarns/0030-basics.yarn
index 34cad9d2..ae553c14 100644
--- a/yarns/0030-basics.yarn
+++ b/yarns/0030-basics.yarn
@@ -19,7 +19,7 @@ program must be able to handle.
 
     SCENARIO backup simple data
     GIVEN 100kB of new data in directory L
-    AND a manifest of directory L in M
+    AND a manifest of L in M
     WHEN user U backs up directory L to repository R
     AND user U restores their latest generation in repository R into X
     THEN L, restored to X, matches manifest M
@@ -46,7 +46,7 @@ more disk space than the one in live data.
 
     SCENARIO backup a sparse file
     GIVEN a file S in L, with a hole, data, a hole
-    AND a manifest of directory L in M
+    AND a manifest of L in M
     WHEN user U backs up directory L to repository R
     AND user U restores their latest generation in repository R into X
     THEN L, restored to X, matches manifest M
@@ -81,7 +81,20 @@ duplication.
 
     SCENARIO backup non-basic filesystem objects
     GIVEN directory L with interesting filesystem objects
-    AND a manifest of directory L in M
+    AND a manifest of L in M
+    WHEN user U backs up directory L to repository R
+    AND user U restores their latest generation in repository R into X
+    THEN L, restored to X, matches manifest M
+
+As a special case, Obnam needs to notice when only an extended
+attribute value changes.
+
+    SCENARIO backup notices when extended attribute value changes
+    GIVEN a file F in L, with data
+    AND file L/F has extended attribute user.foo set to foo
+    WHEN user U backs up directory L to repository R
+    GIVEN file L/F has extended attribute user.foo set to bar
+    AND a manifest of L in M
     WHEN user U backs up directory L to repository R
     AND user U restores their latest generation in repository R into X
     THEN L, restored to X, matches manifest M
@@ -95,8 +108,8 @@ assume that if we can backup two, then it'll all work well.
     SCENARIO backup two roots
     GIVEN directory L1 with interesting filesystem objects
     AND directory L2 with interesting filesystem objects
-    AND a manifest of directory L1 in M1
-    AND a manifest of directory L2 in M2
+    AND a manifest of L1 in M1
+    AND a manifest of L2 in M2
     WHEN user U backs up directories L1 and L2 to repository R
     AND user U restores their latest generation in repository R into X
     THEN L1, restored to X, matches manifest M1
@@ -117,16 +130,17 @@ backup, if the backup finishes successfully.
 Restore a single file
 ---------------------
 
-We need to be able to restore only a single file.
+We need to be able to restore only a single file. Note that when
+restoring a single file, we do not set the parent directory's
+modification time according to the backup, so we need to manipulate
+the manifest to avoid getting an error.
 
     SCENARIO restore a single file
     GIVEN a file F in L, with data
-    AND a manifest of directory L in M
-    AND 100kB of new data in directory L
-    AND manifest M has Mtime for the first entry set from L
+    AND a manifest of L/F in M
     WHEN user U backs up directory L to repository R
     AND user U restores file L/F to X from their latest generation in repository R
-    THEN L, restored to X, matches manifest M
+    THEN L/F, restored to X, matches manifest M
 
 Pretend backing up: the `--pretend` setting
 -------------------------------------------
@@ -139,9 +153,9 @@ than a real one.
     SCENARIO a pretend backup
     GIVEN directory L with interesting filesystem objects
     WHEN user U backs up directory L to repository R
-    GIVEN a manifest of directory R in M1
+    GIVEN a manifest of R in M1
     WHEN user U pretends to back up directory L to repository R
-    GIVEN a manifest of directory R in M2
+    GIVEN a manifest of R in M2
     THEN manifests M1 and M2 match 
 
 Exclude cache directories
@@ -162,7 +176,7 @@ The directory `L` now contains what we want to restore: only the
 wanted data, no cache directory. This is a good time to create the
 manifest.
 
-    AND a manifest of directory L in M
+    AND a manifest of L in M
 
 We now create the cache directory and tag it. Then we backup,
 excluding caches, and restore, and verify. However, there's a snag:
@@ -203,7 +217,7 @@ create one. Test that such timestamps work.
 
     SCENARIO pre-epoch timestamps
     GIVEN file L/file has Unix timestamp -3600
-    AND a manifest of directory L in M
+    AND a manifest of L in M
     WHEN user U backs up directory L to repository R
     AND user U restores their latest generation in repository R into X
     THEN L, restored to X, matches manifest M
@@ -220,7 +234,7 @@ setting to a new size, the backup should still work.
     AND user U sets configuration node-size to 65536
     WHEN user U backs up directory L to repository R
     GIVEN 100Kb of new data in directory L
-    AND a manifest of directory L in M
+    AND a manifest of L in M
     AND user U sets configuration node-size to 4096
     WHEN user U backs up directory L to repository R
     AND user U restores their latest generation in repository R into X
diff --git a/yarns/0040-generations.yarn b/yarns/0040-generations.yarn
index 9c741b4d..7da4f1fb 100644
--- a/yarns/0040-generations.yarn
+++ b/yarns/0040-generations.yarn
@@ -23,10 +23,10 @@ problem.)
 
     SCENARIO backup two generations
     GIVEN 1MB of new data in directory L
-    AND a manifest of directory L in G1
+    AND a manifest of L in G1
     WHEN user U backs up directory L to repository R
     GIVEN 2MB of new data in directory L
-    AND a manifest of directory L in G2
+    AND a manifest of L in G2
     WHEN user U backs up directory L to repository R
     AND user U restores generation 1 to R1 from repository R
     AND user U restores generation 2 to R2 from repository R
@@ -110,10 +110,10 @@ checking that the remaining one is the one we want.
 
     SCENARIO remove specific generations
     GIVEN 1kB of new data in directory L
-    AND a manifest of directory L in M1
+    AND a manifest of L in M1
     WHEN user U backs up directory L to repository R
     GIVEN 1kB of new data in directory L
-    AND a manifest of directory L in M2
+    AND a manifest of L in M2
     WHEN user U backs up directory L to repository R
     AND user U forgets the oldest generation in repository R
     THEN user U sees 1 generation in repository R
@@ -132,7 +132,7 @@ The normal way of forgetting generations is with the `obnam forget
     GIVEN 1kB of new data in directory L
     WHEN user U backs up directory L to repository R
     GIVEN 1kB of new data in directory L
-    AND a manifest of directory L in M
+    AND a manifest of L in M
     WHEN user U backs up directory L to repository R
     AND user U forgets according to schedule 1y in repository R
     THEN user U sees 1 generation in repository R
diff --git a/yarns/0050-multiple-clients.yarn b/yarns/0050-multiple-clients.yarn
index f80ba88a..0cacd464 100644
--- a/yarns/0050-multiple-clients.yarn
+++ b/yarns/0050-multiple-clients.yarn
@@ -14,8 +14,8 @@ suite we do not test concurrency at all.
     SCENARIO two clients sharing a repository
     GIVEN directory L1 with interesting filesystem objects
     AND directory L2 with interesting filesystem objects
-    AND a manifest of directory L1 in M1
-    AND a manifest of directory L2 in M2
+    AND a manifest of L1 in M1
+    AND a manifest of L2 in M2
     WHEN user U1 backs up directory L1 to repository R
     WHEN user U2 backs up directory L2 to repository R
     AND user U1 restores their latest generation in repository R into X1
@@ -28,8 +28,8 @@ a change to both sets of live data, and
 
     GIVEN 1kB of new data in directory L1
     AND 2kB of new data in directory L2
-    AND a manifest of directory L1 in M1A
-    AND a manifest of directory L2 in M2A
+    AND a manifest of L1 in M1A
+    AND a manifest of L2 in M2A
     WHEN user U1 backs up directory L1 to repository R
     AND user U2 backs up directory L2 to repository R
     AND user U1 forgets the oldest generation in repository R
diff --git a/yarns/0060-encryption.yarn b/yarns/0060-encryption.yarn
index 8f7d9b8e..dbdc4c1d 100644
--- a/yarns/0060-encryption.yarn
+++ b/yarns/0060-encryption.yarn
@@ -41,7 +41,7 @@ that encryption is done at the I/O abstraction level.
     SCENARIO basic encrypted backup and restore
     GIVEN user U uses encryption key "Test Key One" from test-data/keyring-1
     AND directory L with interesting filesystem objects
-    AND a manifest of directory L in M
+    AND a manifest of L in M
     WHEN user U backs up directory L to repository R
     AND user U restores their latest generation in repository R into X
     THEN L, restored to X, matches manifest M
@@ -85,11 +85,11 @@ Then we make a backup as the second client.
 
 Let's make sure both clients can still restore their own data.
 
-    GIVEN a manifest of directory L1 in M1
+    GIVEN a manifest of L1 in M1
     WHEN user U1 restores their latest generation in repository R into X1
     THEN L1, restored to X1, matches manifest M1
 
-    GIVEN a manifest of directory L2 in M2
+    GIVEN a manifest of L2 in M2
     WHEN user U2 restores their latest generation in repository R into X2
     THEN L2, restored to X2, matches manifest M2
 
diff --git a/yarns/0100-fuse.yarn b/yarns/0100-fuse.yarn
index 8efe3e40..ef6736d9 100644
--- a/yarns/0100-fuse.yarn
+++ b/yarns/0100-fuse.yarn
@@ -8,7 +8,7 @@ test suite concentrates on verifying that at least the basics work.
     SCENARIO Browsing backups with FUSE plugin
     ASSUMING user is in group fuse
     GIVEN directory L with interesting filesystem objects
-    AND a manifest of directory L in M
+    AND a manifest of L in M
     WHEN user U backs up directory L to repository R
     AND user U FUSE mounts the repository R at F
     THEN L, restored to F/latest, matches manifest M
diff --git a/yarns/9000-implements.yarn b/yarns/9000-implements.yarn
index 65a6f2f3..2932373b 100644
--- a/yarns/9000-implements.yarn
+++ b/yarns/9000-implements.yarn
@@ -82,6 +82,11 @@ UTC format, as is common in Unix.
     os.utime(filename, (timestamp, timestamp))
     '
     
+We need to manipulate extended attributes.
+
+    IMPLEMENTS GIVEN file (\S+) has extended attribute (\S+) set to (\S+)
+    mkdir -p $(dirname "$DATADIR/$MATCH_1")
+    setfattr --name="$MATCH_2" --value "$MATCH_3" "$DATADIR/$MATCH_1"
 
 Manifest creation and checking
 ------------------------------
@@ -91,7 +96,7 @@ that naming of the manifest is explicit. This reduces the need to
 debug weird test suite bugs, when an automatic or implicit manifest
 naming goes wrong.
 
-    IMPLEMENTS GIVEN a manifest of directory (\S+) in (\S+)
+    IMPLEMENTS GIVEN a manifest of (\S+) in (\S+)
     manifest "$DATADIR/$MATCH_1" > "$DATADIR/$MATCH_2"
 
 We need to check a directory tree against an existing manifest. We do
@@ -101,8 +106,14 @@ see what the temporary manifest actually contains. Being able to look
 at the actual file is easier than trying to interpret complicated
 diffs.
 
+We remove the restore directory prefix from the manifest (the `Name:`
+field that Summain outputs). This is necessary so that comparisons
+with **diff**(1) will work well.
+
     IMPLEMENTS THEN (\S+), restored to (\S+), matches manifest (\S+)
-    manifest "$DATADIR/$MATCH_2/$DATADIR/$MATCH_1" > "$DATADIR/temp-manifest"
+    manifest "$DATADIR/$MATCH_2/$DATADIR/$MATCH_1" |
+        sed "s*$DATADIR/$MATCH_2/**" > "$DATADIR/temp-manifest"
+
     diff -u "$DATADIR/$MATCH_3" "$DATADIR/temp-manifest"
     rm -f "$DATADIR/temp-manifest"
 
diff --git a/yarns/obnam.sh b/yarns/obnam.sh
index f05393b2..55fc2336 100644
--- a/yarns/obnam.sh
+++ b/yarns/obnam.sh
@@ -121,7 +121,7 @@ normalise_manifest_times()
 }
 
 
-# Create a manifest with summain of a directory.
+# Create a manifest with summain of a file or a directory.
 
 manifest()
 {