Index: ext/rbu/rbuvacuum.test
==================================================================
--- ext/rbu/rbuvacuum.test
+++ ext/rbu/rbuvacuum.test
@@ -239,10 +239,25 @@
     PRAGMA main.page_size;
     PRAGMA main.auto_vacuum;
     PRAGMA main.user_version;
     PRAGMA main.application_id;
   } {8192 2 412 413}
+
+  # Vacuum a database with a large sqlite_master table.
+  #
+  reset_db
+  do_test 1.10.1 {
+    for {set i 1} {$i < 50} {incr i} {
+      execsql "PRAGMA page_size = 1024"
+      execsql "CREATE TABLE t$i (a, b, c, PRIMARY KEY(a, b));"
+      execsql "
+        INSERT INTO t$i VALUES(1, 2, 3);
+        INSERT INTO t$i VALUES(4, 5, 6);
+      "
+    }
+  } {}
+  do_rbu_vacuum_test 1.10.2 $step
 }
 
 #-------------------------------------------------------------------------
 # Test some error cases:
 #

Index: ext/rbu/sqlite3rbu.c
==================================================================
--- ext/rbu/sqlite3rbu.c
+++ ext/rbu/sqlite3rbu.c
@@ -3950,13 +3950,13 @@
           rbuPutU32(&aBuf[32], 0);          /* first page on free list trunk */
           rbuPutU32(&aBuf[28], 1);          /* size of db file in pages */
           rbuPutU32(&aBuf[24], pRbu->pRbuFd->iCookie+1);  /* Change counter */
 
           if( iAmt>100 ){
-            assert( iAmt>=101 );
-            memset(&aBuf[101], 0, iAmt-101);
+            memset(&aBuf[100], 0, iAmt-100);
             rbuPutU16(&aBuf[105], iAmt & 0xFFFF);
+            aBuf[100] = 0x0D;
           }
         }
       }
 #endif
     }