Merge mysql.com:/home/svoj/devel/mysql/BUG26881/mysql-4.1-engines

into  mysql.com:/home/svoj/devel/mysql/BUG26881/mysql-5.0-engines

myisam/mi_create.c

@@ -157,6 +157,10 @@ int mi_create(const char *name,uint keys,MI_KEYDEF *keydefs,
       rec--;
       if (rec->type == (int) FIELD_SKIP_ZERO && rec->length == 1)
       {
+        /*
+          NOTE1: here we change a field type FIELD_SKIP_ZERO ->
+          FIELD_NORMAL
+        */
 	rec->type=(int) FIELD_NORMAL;
 	packed--;
 	min_pack_length++;

mysql-test/r/merge.result

@@ -808,6 +808,19 @@ CREATE TABLE t2(c1 INT) ENGINE=MERGE UNION=(t1);
 INSERT DELAYED INTO t2 VALUES(1);
 ERROR HY000: Table storage engine for 't2' doesn't have this option
 DROP TABLE t1, t2;
+CREATE TABLE t1(c1 VARCHAR(1));
+CREATE TABLE m1 LIKE t1;
+ALTER TABLE m1 ENGINE=MERGE UNION=(t1);
+SELECT * FROM m1;
+c1
+DROP TABLE t1, m1;
+CREATE TABLE t1(c1 VARCHAR(4), c2 TINYINT, c3 TINYINT, c4 TINYINT,
+c5 TINYINT, c6 TINYINT, c7 TINYINT, c8 TINYINT, c9 TINYINT);
+CREATE TABLE m1 LIKE t1;
+ALTER TABLE m1 ENGINE=MERGE UNION=(t1);
+SELECT * FROM m1;
+c1	c2	c3	c4	c5	c6	c7	c8	c9
+DROP TABLE t1, m1;
 create table t1 (b bit(1));
 create table t2 (b bit(1));
 create table tm (b bit(1)) engine = merge union = (t1,t2);

mysql-test/t/merge.test

@@ -439,6 +439,23 @@ CREATE TABLE t2(c1 INT) ENGINE=MERGE UNION=(t1);
 INSERT DELAYED INTO t2 VALUES(1);
 DROP TABLE t1, t2;
 
+#
+# BUG#26881 - Large MERGE tables report incorrect specification when no
+#             differences in tables
+#
+CREATE TABLE t1(c1 VARCHAR(1));
+CREATE TABLE m1 LIKE t1;
+ALTER TABLE m1 ENGINE=MERGE UNION=(t1);
+SELECT * FROM m1;
+DROP TABLE t1, m1;
+
+CREATE TABLE t1(c1 VARCHAR(4), c2 TINYINT, c3 TINYINT, c4 TINYINT,
+                c5 TINYINT, c6 TINYINT, c7 TINYINT, c8 TINYINT, c9 TINYINT);
+CREATE TABLE m1 LIKE t1;
+ALTER TABLE m1 ENGINE=MERGE UNION=(t1);
+SELECT * FROM m1;
+DROP TABLE t1, m1;
+
 # End of 4.1 tests
 
 #

sql/ha_myisam.cc

@@ -342,6 +342,12 @@ int table2myisam(TABLE *table_arg, MI_KEYDEF **keydef_out,
   RETURN VALUE
     0 - Equal definitions.
     1 - Different definitions.
+
+  TODO
+    - compare FULLTEXT keys;
+    - compare SPATIAL keys;
+    - compare FIELD_SKIP_ZERO which is converted to FIELD_NORMAL correctly
+      (should be corretly detected in table2myisam).
 */
 
 int check_definition(MI_KEYDEF *t1_keyinfo, MI_COLUMNDEF *t1_recinfo,
@@ -367,6 +373,28 @@ int check_definition(MI_KEYDEF *t1_keyinfo, MI_COLUMNDEF *t1_recinfo,
   {
     HA_KEYSEG *t1_keysegs= t1_keyinfo[i].seg;
     HA_KEYSEG *t2_keysegs= t2_keyinfo[i].seg;
+    if (t1_keyinfo[i].flag & HA_FULLTEXT && t2_keyinfo[i].flag & HA_FULLTEXT)
+      continue;
+    else if (t1_keyinfo[i].flag & HA_FULLTEXT ||
+             t2_keyinfo[i].flag & HA_FULLTEXT)
+    {
+       DBUG_PRINT("error", ("Key %d has different definition", i));
+       DBUG_PRINT("error", ("t1_fulltext= %d, t2_fulltext=%d",
+                            test(t1_keyinfo[i].flag & HA_FULLTEXT),
+                            test(t2_keyinfo[i].flag & HA_FULLTEXT)));
+       DBUG_RETURN(1);
+    }
+    if (t1_keyinfo[i].flag & HA_SPATIAL && t2_keyinfo[i].flag & HA_SPATIAL)
+      continue;
+    else if (t1_keyinfo[i].flag & HA_SPATIAL ||
+             t2_keyinfo[i].flag & HA_SPATIAL)
+    {
+       DBUG_PRINT("error", ("Key %d has different definition", i));
+       DBUG_PRINT("error", ("t1_spatial= %d, t2_spatial=%d",
+                            test(t1_keyinfo[i].flag & HA_SPATIAL),
+                            test(t2_keyinfo[i].flag & HA_SPATIAL)));
+       DBUG_RETURN(1);
+    }
     if (t1_keyinfo[i].keysegs != t2_keyinfo[i].keysegs ||
         t1_keyinfo[i].key_alg != t2_keyinfo[i].key_alg)
     {
@@ -403,7 +431,14 @@ int check_definition(MI_KEYDEF *t1_keyinfo, MI_COLUMNDEF *t1_recinfo,
   {
     MI_COLUMNDEF *t1_rec= &t1_recinfo[i];
     MI_COLUMNDEF *t2_rec= &t2_recinfo[i];
-    if (t1_rec->type != t2_rec->type ||
+    /*
+      FIELD_SKIP_ZERO can be changed to FIELD_NORMAL in mi_create,
+      see NOTE1 in mi_create.c
+    */
+    if ((t1_rec->type != t2_rec->type &&
+         !(t1_rec->type == (int) FIELD_SKIP_ZERO &&
+           t1_rec->length == 1 &&
+           t2_rec->type == (int) FIELD_NORMAL)) ||
         t1_rec->length != t2_rec->length ||
         t1_rec->null_bit != t2_rec->null_bit)
     {