# 
# patch "ChangeLog"
#  from [540734e35347771f3329c0afc13962e026cc88af]
#    to [763634239be07147982294a75d4ab0ed31719c2e]
# 
# patch "schema_migration.cc"
#  from [dbe70c577761111a22e6bc47649411c335399bdf]
#    to [f9205058568c4e8b4b496d8b655a870f05edf0be]
# 
--- ChangeLog
+++ ChangeLog
@@ -1,5 +1,10 @@
 2005-07-12  Nathaniel Smith  <address@hidden>
 
+	* schema_migration.cc (migrator::migrate): When there is nothing
+	to be done, do nothing.
+
+2005-07-12  Nathaniel Smith  <address@hidden>
+
 	* netsync.cc (rebuild_merkle_trees): Reduce memory usage a bit,
 	and don't insert branch certs that the other side will just end up
 	throwing away (reduces network traffic).
--- schema_migration.cc
+++ schema_migration.cc
@@ -14,6 +14,7 @@
 
 #include <sqlite3.h>
 
+#include "sanity.hh"
 #include "schema_migration.hh"
 #include "cryptopp/filters.h"
 #include "cryptopp/sha.h"
@@ -188,11 +189,17 @@
   void migrate(sqlite3 *sql, string target_id)
   {
     string init;
-    calculate_schema_id(sql, init);
 
     if (sql == NULL)
       throw runtime_error("NULL sqlite object given to migrate");
 
+    calculate_schema_id(sql, init);
+    if (target_id == init)
+      {
+        P(F("nothing to migrate; schema %s is up-to-date\n") % init);
+        return;
+      }
+
     if (sqlite3_create_function(sql, "sha1", -1, SQLITE_UTF8, NULL,
             &sqlite_sha1_fn, NULL, NULL))
       throw runtime_error("error registering sha1 function with sqlite");