diff --git a/memo b/memo
index 38c9a02..c7ad7df 100755
--- a/memo
+++ b/memo
@@ -343,11 +343,12 @@ def cmd_wake(d, args):
                     % (T, plural(now, "entry")))
     # A part is rendered as of T, so a note landing between two parts cannot
     # shift a boundary and drop a line.
-    n = pending_count(d, T)
-    if n:
+    nap = next_nap(d, T)
+    if nap:
+        n = max(1, pending_count(d, T))
         print("Cannot wake: %s pending. Do %s, then run memo wake again.\n"
               % (plural(n, "compression"), "it" if n == 1 else "them"))
-        print(next_nap(d, T))
+        print(nap)
         sys.exit(1)
     if not T:
         print("No memories yet. Record the first with: memo note \"<one line>\"")
@@ -403,11 +404,14 @@ def cmd_sleep(d, args):
             print("Nothing left to compress.")
             return
         if (lo, hi) != todo[0]:
-            die("Wrong block: %s. Blocks are built in order; the next is "
-                "%d-%d. Run: memo sleep"
-                % (args[0], todo[0][0], todo[0][1] - 1))
-        if not tree_put(d, lo, hi, check(args[1])):
-            print("Another session already wrote %d-%d." % (lo, hi - 1))
+            if tree_get(d, lo, hi) is not None:
+                print("%d-%d is already settled." % (lo, hi - 1))
+            else:
+                die("Wrong block: %s. Blocks are built in order; the next is "
+                    "%d-%d. Run: memo sleep"
+                    % (args[0], todo[0][0], todo[0][1] - 1))
+        elif not tree_put(d, lo, hi, check(args[1])):
+            print("%d-%d was settled or forgotten meanwhile." % (lo, hi - 1))
         else:
             print("%d-%d saved." % (lo, hi - 1))
     nap = next_nap(d, T)
@@ -445,7 +449,8 @@ def cmd_recall(d, args):
         pat = re.compile(args[0], re.I)
     except re.error as e:
         die("bad regex: %s" % e)
-    hits = [e for e in log_slice(d, 0, log_len(d)) if pat.search(e[2])]
+    hits = [e for e in log_slice(d, 0, log_len(d))
+            if pat.search("#%d %s %s" % e)]
     if not hits:
         print("No match.")
         return
diff --git a/test.py b/test.py
index c35772c..34e0141 100755
--- a/test.py
+++ b/test.py
@@ -167,6 +167,7 @@ check(r.returncode == 1 and "Cannot wake" in r.stdout,
       "wake must refuse while work is pending")
 check("run memo wake again" in r.stdout,
       "the refusal must order the agent back to wake")
+check("None" not in r.stdout, "the refusal printed a Python None")
 
 # sleep loop, with a fake compressor
 naps = 0
@@ -229,10 +230,17 @@ r = run("sleep", "0-1", "attempted overwrite")
 check(r.returncode == 0 and "Nothing left to compress" in r.stdout,
       "sleep with nothing pending must say so and write nothing")
 
-# recall reaches memories the summaries lost
+# recall reaches memories the summaries lost, and matches the whole line:
+# id and date included, not just the text
 r = run("recall", "memory number 7,")
 check(r.returncode == 0 and "#7 " in r.stdout, "recall missed a memory")
 check("1 match." in r.stdout, "a single match is not `1 matches`: " + r.stdout)
+r = run("recall", "^#7 ")
+check("memory number 7," in r.stdout, "recall cannot find a memory by id")
+r = run("recall", "2020-01-02")
+check("#7 " in r.stdout and "5 matches." in r.stdout,
+      "recall cannot find memories by date: " + r.stdout)
+
 
 def treesize():
     t = os.path.join(d, "TREE")
@@ -244,11 +252,18 @@ check("16-31" in r.stdout, "forget did not report the block: " + r.stdout + r.st
 check(treesize() < before, "forget did not shrink the tree")
 check(os.path.getsize(os.path.join(d, "LOG.txt")) == logsize, "forget touched the log")
 check(run("wake").returncode == 1, "wake should refuse after a forget")
-# a block already settled cannot be rewritten: only the first pending block
-# is ever accepted
+# a settled block cannot be rewritten. Resubmitting one (two sessions paid
+# the same nap) is not an error: say it is settled, write nothing
+mid = treesize()
 r = run("sleep", "0-1", "attempted overwrite")
+check(r.returncode == 0 and "already settled" in r.stdout,
+      "resubmitting a settled block was not reported as settled: " + r.stderr)
+check(treesize() == mid, "resubmitting a settled block wrote something")
+# a block that is neither settled nor next (here: a dropped ancestor,
+# submitted before its half is rebuilt) is a real mistake
+r = run("sleep", "0-31", "out of order")
 check(r.returncode == 1 and "Wrong block" in r.stderr,
-      "rewriting a settled block was allowed")
+      "an out-of-order block was accepted")
 n = 0
 while True:
     r = run("sleep")