branches/zip: row_undo_mod_del_mark_or_remove_sec_low(): Do not

complain if the record is not found.  Explain that this is possible
when a deadlock occurs during an update.  Heikki investigated this
in Issue #134.

row/row0umod.c

@@ -316,26 +316,11 @@ row_undo_mod_del_mark_or_remove_sec_low(
 		be missing if the UPDATE did not have time to insert
 		the secondary index records before the crash.  When we
 		are undoing that UPDATE in crash recovery, the record
-		may be missing.  In normal processing, the record
-		SHOULD exist. */
-		trx_t*	trx = thr_get_trx(thr);
-
-		if (!trx_is_recv(trx)) {
-			fputs("InnoDB: error in sec index entry del undo in\n"
-			      "InnoDB: ", stderr);
-			dict_index_name_print(stderr, trx, index);
-			fputs("\n"
-			      "InnoDB: tuple ", stderr);
-			dtuple_print(stderr, entry);
-			fputs("\n"
-			      "InnoDB: record ", stderr);
-			rec_print(stderr, btr_pcur_get_rec(&pcur), index);
-			putc('\n', stderr);
-			trx_print(stderr, trx, 0);
-			fputs("\n"
-			      "InnoDB: Submit a detailed bug report"
-			      " to http://bugs.mysql.com\n", stderr);
-		}
+		may be missing.
+
+		In normal processing, if an update ends in a deadlock
+		before it has inserted all updated secondary index
+		records, then the undo will not find those records. */
 
 		btr_pcur_close(&pcur);
 		mtr_commit(&mtr);