Applying InnoDB snapshot, fixes BUG#51378.

Detailed revision comments:

r6789 | jyang | 2010-03-10 11:18:18 +0200 (Wed, 10 Mar 2010) | 10 lines
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.

storage/innodb_plugin/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 @@ ha_innobase::open(
 	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;
 

storage/innodb_plugin/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;