MDEV-8565: COLUMN_CHECK fails on valid data

Check allows zero lengts int/uint now.

mysql-test/r/dyncol.result

@@ -1805,5 +1805,20 @@ set     impressions = column_add(impressions,
         );
 drop table t1;
 #
+# MDEV-8565: COLUMN_CHECK fails on valid data
+#
+SELECT COLUMN_CHECK(COLUMN_CREATE('a',0,'b','1'));
+COLUMN_CHECK(COLUMN_CREATE('a',0,'b','1'))
+1
+SELECT COLUMN_CHECK(COLUMN_CREATE('a',1,'b','1'));
+COLUMN_CHECK(COLUMN_CREATE('a',1,'b','1'))
+1
+SELECT COLUMN_JSON(COLUMN_CREATE('a',0,'b','1'));
+COLUMN_JSON(COLUMN_CREATE('a',0,'b','1'))
+{"a":0,"b":"1"}
+SELECT COLUMN_JSON(COLUMN_CREATE('a',1,'b','1'));
+COLUMN_JSON(COLUMN_CREATE('a',1,'b','1'))
+{"a":1,"b":"1"}
+#
 # end of 10.0 tests
 #

mysql-test/t/dyncol.test

@@ -871,6 +871,18 @@ set     impressions = column_add(impressions,
 
 drop table t1;
 
+--echo #
+--echo # MDEV-8565: COLUMN_CHECK fails on valid data
+--echo #
+
+SELECT COLUMN_CHECK(COLUMN_CREATE('a',0,'b','1'));
+
+SELECT COLUMN_CHECK(COLUMN_CREATE('a',1,'b','1'));
+
+SELECT COLUMN_JSON(COLUMN_CREATE('a',0,'b','1'));
+
+SELECT COLUMN_JSON(COLUMN_CREATE('a',1,'b','1'));
+
 --echo #
 --echo # end of 10.0 tests
 --echo #

mysys/ma_dyncol.c

@@ -3723,10 +3723,12 @@ mariadb_dyncol_check(DYNAMIC_COLUMN *str)
     if (prev_type != DYN_COL_NULL)
     {
       /* It is not first entry */
-      if (prev_data_offset >= data_offset)
+      if (prev_data_offset > data_offset ||
+          ((prev_type !=  DYN_COL_INT &&
+            prev_type != DYN_COL_UINT) && prev_data_offset == data_offset))
       {
         DBUG_PRINT("info", ("Field order: %u  Previous data offset: %u"
-                            " >= Current data offset: %u",
+                            " >(=) Current data offset: %u",
                             (uint)i,
                             (uint)prev_data_offset,
                             (uint)data_offset));