InnoDB: Keep the "compact format" flag in SYS_TABLES.N_COLS

instead of SYS_TABLES.MIX_LEN, because the latter was not
initialized to zero in old MySQL 3.23 releases. This will break
existing MySQL/InnoDB 5.0.3-bk databases for which
SHOW TABLE STATUS displays Row_format=Compact.


innobase/dict/dict0crea.c:
  Write the "compact format" flag to N_COLS instead of MIX_LEN.
  Remove corruption analysis for MIX_LEN, as it has been tracked down
  to MySQL 3.23.4x not initializing MIX_LEN.
innobase/dict/dict0load.c:
  Read the "compact format" flag from N_COLS instead of MIX_LEN.

1 files changed, 7 insertions, 7 deletions

diff --git a/innobase/dict/dict0load.c b/innobase/dict/dict0load.c
index b33111b1ff1..1622ffa5454 100644
--- a/innobase/dict/dict0load.c
+++ b/innobase/dict/dict0load.c
@@ -818,8 +818,10 @@ dict_load_table(
 	field = rec_get_nth_field_old(rec, 4, &len);
 	n_cols = mach_read_from_4(field);
 
-	/* table->comp will be initialized later, in this function */
-	table = dict_mem_table_create(name, space, n_cols, FALSE);
+	/* The high-order bit of N_COLS is the "compact format" flag. */
+	table = dict_mem_table_create(name, space,
+					n_cols & ~0x80000000UL,
+					!!(n_cols & 0x80000000UL));
 
 	table->ibd_file_missing = ibd_file_missing;
 
@@ -844,14 +846,12 @@ dict_load_table(
 #endif
 	}
 
-	/* The high-order bit of MIX_LEN is the "compact format" flag */
-	field = rec_get_nth_field_old(rec, 7, &len);
-	table->comp = !!(mach_read_from_1(field) & 0x80);
-
 	if ((table->type == DICT_TABLE_CLUSTER)
 	    || (table->type == DICT_TABLE_CLUSTER_MEMBER)) {
 
-		table->mix_len = mach_read_from_4(field) & 0x7fffffff;
+		field = rec_get_nth_field_old(rec, 7, &len);
+		ut_a(len == 4);
+		table->mix_len = mach_read_from_4(field);
 	}
 
 	btr_pcur_close(&pcur);