[t:3647] [t:3728] merge changes from tokudb.3647, closes #3647 and closes #3728

git-svn-id: file:///svn/toku/tokudb@33053 c7de825b-a66e-492c-adef-691d508d4ae1

newbrt/cachetable.c

@@ -1907,7 +1907,7 @@ int toku_cachetable_get_and_pin_nonblocking (
     int r = cachetable_fetch_pair(ct, cf, p, fetch_callback, read_extraargs);
     cachetable_unlock(ct);
     if (ct->ydb_lock_callback) ct->ydb_lock_callback();
-    if (r!=0) return r;
+    if (r!=0) { assert(!p->checkpoint_pending); return r; }
     else return TOKUDB_TRY_AGAIN;
 }