dict0load.c, dict0crea.c:

  Add diagnostic code to track corruption in mix_len; it was reported on the mailing list Jan 14, 2005

innobase/dict/dict0crea.c

@@ -81,6 +81,17 @@ dict_create_sys_tables_tuple(
 
 	dfield_set_data(dfield, ptr, 8);
 	/* 7: MIX_LEN --------------------------*/
+
+	/* Track corruption reported on mailing list Jan 14, 2005 */
+	if (table->mix_len != 0 && table->mix_len != 0x80000000) {
+		fprintf(stderr,
+"InnoDB: Error: mix_len is %lu in table %s\n", (ulong)table->mix_len,
+							table->name);
+		mem_analyze_corruption((byte*)&(table->mix_len));
+	
+		ut_error;
+	}
+
 	dfield = dtuple_get_nth_field(entry, 5);
 
 	ptr = mem_heap_alloc(heap, 4);

innobase/dict/dict0load.c

@@ -729,6 +729,7 @@ dict_load_table(
 	ulint		space;
 	ulint		n_cols;
 	ulint		err;
+	ulint		mix_len;
 	mtr_t		mtr;
 	
 #ifdef UNIV_SYNC_DEBUG
@@ -775,6 +776,22 @@ dict_load_table(
 		return(NULL);
 	}
 
+	/* Track a corruption bug reported on the MySQL mailing list Jan 14,
+	2005: mix_id had a value different from 0 */
+
+	field = rec_get_nth_field(rec, 7, &len);
+	ut_a(len == 4);
+
+	mix_len = mach_read_from_4(field);
+
+	if (mix_len != 0 && mix_len != 0x80000000) {
+		ut_print_timestamp(stderr);
+		
+		fprintf(stderr,
+			"  InnoDB: table %s has a nonsensical mix len %lu\n",
+			name, (ulong)mix_len);
+	}
+
 #if MYSQL_VERSION_ID < 50300
 	/* Starting from MySQL 5.0.3, the high-order bit of MIX_LEN is the
 	"compact format" flag. */