branches/zip: If a unique index is on a column prefix, such

unique index cannot be upgrade to primary index even if there
is no primary index already defined. Also fix possible corruption
when initialize "ref_length" value in case there is a mismatch
between MySQL and InnoDB primary key. Fix bug #51378: "Init
'ref_length'  to correct value, in case an out of bound MySQL
primary_key".
rb://262 approved by Marko.

handler/ha_innodb.cc

@@ -3304,6 +3304,9 @@ ha_innobase::innobase_initialize_autoinc()
 		ulint		err;
 
 		update_thd(ha_thd());
+
+		ut_a(prebuilt->trx == thd_to_trx(user_thd));
+
 		col_name = field->field_name;
 		index = innobase_get_index(table->s->next_number_index);
 
@@ -3494,31 +3497,86 @@ retry:
 	of length ref_length! */
 
 	if (!row_table_got_default_clust_index(ib_table)) {
-		if (primary_key >= MAX_KEY) {
-		  sql_print_error("Table %s has a primary key in InnoDB data "
-				  "dictionary, but not in MySQL!", name);
-		}
 
 		prebuilt->clust_index_was_generated = FALSE;
 
-		/* MySQL allocates the buffer for ref. key_info->key_length
-		includes space for all key columns + one byte for each column
-		that may be NULL. ref_length must be as exact as possible to
-		save space, because all row reference buffers are allocated
-		based on ref_length. */
+		if (UNIV_UNLIKELY(primary_key >= MAX_KEY)) {
+			sql_print_error("Table %s has a primary key in "
+					"InnoDB data dictionary, but not "
+					"in MySQL!", name);
+
+			/* This mismatch could cause further problems
+			if not attended, bring this to the user's attention
+			by printing a warning in addition to log a message
+			in the errorlog */
+			push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_WARN,
+					    ER_NO_SUCH_INDEX,
+					    "InnoDB: Table %s has a "
+					    "primary key in InnoDB data "
+					    "dictionary, but not in "
+					    "MySQL!", name);
+
+			/* If primary_key >= MAX_KEY, its (primary_key)
+			value could be out of bound if continue to index
+			into key_info[] array. Find InnoDB primary index,
+			and assign its key_length to ref_length.
+			In addition, since MySQL indexes are sorted starting
+			with primary index, unique index etc., initialize
+			ref_length to the first index key length in
+			case we fail to find InnoDB cluster index.
+
+			Please note, this will not resolve the primary
+			index mismatch problem, other side effects are
+			possible if users continue to use the table.
+			However, we allow this table to be opened so
+			that user can adopt necessary measures for the
+			mismatch while still being accessible to the table
+			date. */
+			ref_length = table->key_info[0].key_length;
+
+			/* Find correspoinding cluster index
+			key length in MySQL's key_info[] array */
+			for (ulint i = 0; i < table->s->keys; i++) {
+				dict_index_t*	index;
+				index = innobase_get_index(i);
+				if (dict_index_is_clust(index)) {
+					ref_length =
+						 table->key_info[i].key_length;
+				}
+			}
+		} else {
+			/* MySQL allocates the buffer for ref.
+			key_info->key_length includes space for all key
+			columns + one byte for each column that may be
+			NULL. ref_length must be as exact as possible to
+			save space, because all row reference buffers are
+			allocated based on ref_length. */
 
-		ref_length = table->key_info[primary_key].key_length;
+			ref_length = table->key_info[primary_key].key_length;
+		}
 	} else {
 		if (primary_key != MAX_KEY) {
-		  sql_print_error("Table %s has no primary key in InnoDB data "
-				  "dictionary, but has one in MySQL! If you "
-				  "created the table with a MySQL version < "
-				  "3.23.54 and did not define a primary key, "
-				  "but defined a unique key with all non-NULL "
-				  "columns, then MySQL internally treats that "
-				  "key as the primary key. You can fix this "
-				  "error by dump + DROP + CREATE + reimport "
-				  "of the table.", name);
+			sql_print_error(
+				"Table %s has no primary key in InnoDB data "
+				"dictionary, but has one in MySQL! If you "
+				"created the table with a MySQL version < "
+				"3.23.54 and did not define a primary key, "
+				"but defined a unique key with all non-NULL "
+				"columns, then MySQL internally treats that "
+				"key as the primary key. You can fix this "
+				"error by dump + DROP + CREATE + reimport "
+				"of the table.", name);
+
+			/* This mismatch could cause further problems
+			if not attended, bring this to the user attention
+			by printing a warning in addition to log a message
+			in the errorlog */
+			push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_WARN,
+					    ER_NO_SUCH_INDEX,
+					    "InnoDB: Table %s has no "
+					    "primary key in InnoDB data "
+					    "dictionary, but has one in "
+					    "MySQL!", name);
 		}
 
 		prebuilt->clust_index_was_generated = TRUE;
@@ -5402,9 +5460,6 @@ ha_innobase::innobase_get_index(
 	DBUG_ENTER("innobase_get_index");
 	ha_statistic_increment(&SSV::ha_read_key_count);
 
-	ut_ad(user_thd == ha_thd());
-	ut_a(prebuilt->trx == thd_to_trx(user_thd));
-
 	if (keynr != MAX_KEY && table->s->keys > 0) {
 		key = table->key_info + keynr;
 

handler/handler0alter.cc

@@ -528,12 +528,14 @@ innobase_create_key_def(
 				     key_info->name, "PRIMARY");
 
 	/* If there is a UNIQUE INDEX consisting entirely of NOT NULL
-	columns, MySQL will treat it as a PRIMARY KEY unless the
-	table already has one. */
+	columns and if the index does not contain column prefix(es)
+	(only prefix/part of the column is indexed), MySQL will treat the
+	index as a PRIMARY KEY unless the table already has one. */
 
 	if (!new_primary && (key_info->flags & HA_NOSAME)
+	    && (!(key_info->flags & HA_KEY_HAS_PART_KEY_SEG))
 	    && row_table_got_default_clust_index(table)) {
-		uint	key_part = key_info->key_parts;
+		uint    key_part = key_info->key_parts;
 
 		new_primary = TRUE;
 

mysql-test/innodb_bug51378.result

+create table bug51378 (
+col1 int not null,
+col2 blob not null,
+col3 time not null) engine = innodb;
+create unique index idx on bug51378(col1, col2(31));
+alter table bug51378 add unique index idx2(col1, col2(31));
+create unique index idx3 on bug51378(col1, col3);
+SHOW CREATE TABLE bug51378;
+Table	Create Table
+bug51378	CREATE TABLE `bug51378` (
+  `col1` int(11) NOT NULL,
+  `col2` blob NOT NULL,
+  `col3` time NOT NULL,
+  UNIQUE KEY `idx3` (`col1`,`col3`),
+  UNIQUE KEY `idx` (`col1`,`col2`(31)),
+  UNIQUE KEY `idx2` (`col1`,`col2`(31))
+) ENGINE=InnoDB DEFAULT CHARSET=latin1
+drop index idx3 on bug51378;
+SHOW CREATE TABLE bug51378;
+Table	Create Table
+bug51378	CREATE TABLE `bug51378` (
+  `col1` int(11) NOT NULL,
+  `col2` blob NOT NULL,
+  `col3` time NOT NULL,
+  UNIQUE KEY `idx` (`col1`,`col2`(31)),
+  UNIQUE KEY `idx2` (`col1`,`col2`(31))
+) ENGINE=InnoDB DEFAULT CHARSET=latin1
+alter table bug51378 add primary key idx3(col1, col2(31));
+SHOW CREATE TABLE bug51378;
+Table	Create Table
+bug51378	CREATE TABLE `bug51378` (
+  `col1` int(11) NOT NULL,
+  `col2` blob NOT NULL,
+  `col3` time NOT NULL,
+  PRIMARY KEY (`col1`,`col2`(31)),
+  UNIQUE KEY `idx` (`col1`,`col2`(31)),
+  UNIQUE KEY `idx2` (`col1`,`col2`(31))
+) ENGINE=InnoDB DEFAULT CHARSET=latin1
+drop table bug51378;
+create table bug51378 (
+col1 int not null,
+col2 blob not null,
+col3 time not null, primary key(col1, col2(31))) engine = innodb;
+create unique index idx on bug51378(col1, col2(31));
+SHOW CREATE TABLE bug51378;
+Table	Create Table
+bug51378	CREATE TABLE `bug51378` (
+  `col1` int(11) NOT NULL,
+  `col2` blob NOT NULL,
+  `col3` time NOT NULL,
+  PRIMARY KEY (`col1`,`col2`(31)),
+  UNIQUE KEY `idx` (`col1`,`col2`(31))
+) ENGINE=InnoDB DEFAULT CHARSET=latin1
+drop table bug51378;
+create table bug51378 (
+col1 int not null,
+col2 int ) engine = innodb;
+create unique index idx on bug51378(col1, col2);
+SHOW CREATE TABLE bug51378;
+Table	Create Table
+bug51378	CREATE TABLE `bug51378` (
+  `col1` int(11) NOT NULL,
+  `col2` int(11) DEFAULT NULL,
+  UNIQUE KEY `idx` (`col1`,`col2`)
+) ENGINE=InnoDB DEFAULT CHARSET=latin1
+drop table bug51378;

mysql-test/innodb_bug51378.test

+# This is the test for bug 51378. Unique index created
+# through "create index" and "alter table add unique index"
+# interfaces should not be treated as primary index if indexed
+# columns contain one or more column prefix(es) (only prefix/part of
+# the column is indexed)
+# On the other hand, if there is a unique index covers all
+# columns of a table, and they are non-null columns, and
+# full length of the column are indexed, then this index
+# will be created as primary index
+# Following queries test various scenario, no mismatch
+# error message should be printed.
+--source include/have_innodb.inc
+
+# Create a table contains a BLOB column
+create table bug51378 (
+	col1 int not null,
+	col2 blob not null,
+	col3 time not null) engine = innodb;
+
+# Create following unique indexes on 'col1' and 'col2(31)'
+# of the table, the index should not be treated as primary
+# key because it indexes only first 31 bytes of col2.
+# Thus it contains "column prefix", and will not be
+# upgraded to primary index.
+# There should not be mismatch message printed in the
+# errorlog
+create unique index idx on bug51378(col1, col2(31));
+
+alter table bug51378 add unique index idx2(col1, col2(31));
+
+# Unique index on 'col1' and 'col3' will be created as primary index,
+# since the index does not contain column prefix
+create unique index idx3 on bug51378(col1, col3);
+
+# Show create table would show idx3 created as unique index, internally,
+# idx3 is treated as primary index both by MySQL and Innodb
+SHOW CREATE TABLE bug51378;
+
+# "GEN_CLUST_INDEX" will be re-created as default primary index
+# after idx3 is dropped
+drop index idx3 on bug51378;
+
+SHOW CREATE TABLE bug51378;
+
+# Or we can add the primary key through alter table interfaces
+alter table bug51378 add primary key idx3(col1, col2(31));
+
+SHOW CREATE TABLE bug51378;
+
+drop table bug51378;
+
+# Or we can create such primary key through create table interfaces
+create table bug51378 (
+        col1 int not null,
+        col2 blob not null,
+        col3 time not null, primary key(col1, col2(31))) engine = innodb;
+
+# Unique index on one or more column prefix(es) will be created
+# as non-cluster index
+create unique index idx on bug51378(col1, col2(31));
+
+SHOW CREATE TABLE bug51378;
+
+drop table bug51378;
+
+# If a table has a NULLABLE column, unique index on it will not
+# be treated as primary index.
+create table bug51378 (
+	col1 int not null,
+        col2 int ) engine = innodb;
+
+# This will be created as non-cluster index since col2 is nullable
+create unique index idx on bug51378(col1, col2);
+
+SHOW CREATE TABLE bug51378;
+
+drop table bug51378;