1 files changed, 612 insertions, 17 deletions

diff --git a/storage/xtradb/btr/btr0btr.c b/storage/xtradb/btr/btr0btr.c
index 2fb14b06a7b..396ad422010 100644
--- a/storage/xtradb/btr/btr0btr.c
+++ b/storage/xtradb/btr/btr0btr.c
@@ -1,6 +1,6 @@
 /*****************************************************************************
 
-Copyright (c) 1994, 2010, Innobase Oy. All Rights Reserved.
+Copyright (c) 1994, 2011, Oracle and/or its affiliates. All Rights Reserved.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -42,6 +42,560 @@ Created 6/2/1994 Heikki Tuuri
 #include "ibuf0ibuf.h"
 #include "trx0trx.h"
 
+#ifdef UNIV_BLOB_DEBUG
+# include "srv0srv.h"
+# include "ut0rbt.h"
+
+/** TRUE when messages about index->blobs modification are enabled. */
+static ibool btr_blob_dbg_msg;
+
+/** Issue a message about an operation on index->blobs.
+@param op	operation
+@param b	the entry being subjected to the operation
+@param ctx	the context of the operation */
+#define btr_blob_dbg_msg_issue(op, b, ctx)			\
+	fprintf(stderr, op " %u:%u:%u->%u %s(%u,%u,%u)\n",	\
+		(b)->ref_page_no, (b)->ref_heap_no,		\
+		(b)->ref_field_no, (b)->blob_page_no, ctx,	\
+		(b)->owner, (b)->always_owner, (b)->del)
+
+/** Insert to index->blobs a reference to an off-page column.
+@param index	the index tree
+@param b	the reference
+@param ctx	context (for logging) */
+UNIV_INTERN
+void
+btr_blob_dbg_rbt_insert(
+/*====================*/
+	dict_index_t*		index,	/*!< in/out: index tree */
+	const btr_blob_dbg_t*	b,	/*!< in: the reference */
+	const char*		ctx)	/*!< in: context (for logging) */
+{
+	if (btr_blob_dbg_msg) {
+		btr_blob_dbg_msg_issue("insert", b, ctx);
+	}
+	mutex_enter(&index->blobs_mutex);
+	rbt_insert(index->blobs, b, b);
+	mutex_exit(&index->blobs_mutex);
+}
+
+/** Remove from index->blobs a reference to an off-page column.
+@param index	the index tree
+@param b	the reference
+@param ctx	context (for logging) */
+UNIV_INTERN
+void
+btr_blob_dbg_rbt_delete(
+/*====================*/
+	dict_index_t*		index,	/*!< in/out: index tree */
+	const btr_blob_dbg_t*	b,	/*!< in: the reference */
+	const char*		ctx)	/*!< in: context (for logging) */
+{
+	if (btr_blob_dbg_msg) {
+		btr_blob_dbg_msg_issue("delete", b, ctx);
+	}
+	mutex_enter(&index->blobs_mutex);
+	ut_a(rbt_delete(index->blobs, b));
+	mutex_exit(&index->blobs_mutex);
+}
+
+/**************************************************************//**
+Comparator for items (btr_blob_dbg_t) in index->blobs.
+The key in index->blobs is (ref_page_no, ref_heap_no, ref_field_no).
+@return negative, 0 or positive if *a<*b, *a=*b, *a>*b */
+static
+int
+btr_blob_dbg_cmp(
+/*=============*/
+	const void*	a,	/*!< in: first btr_blob_dbg_t to compare */
+	const void*	b)	/*!< in: second btr_blob_dbg_t to compare */
+{
+	const btr_blob_dbg_t*	aa	= a;
+	const btr_blob_dbg_t*	bb	= b;
+
+	ut_ad(aa != NULL);
+	ut_ad(bb != NULL);
+
+	if (aa->ref_page_no != bb->ref_page_no) {
+		return(aa->ref_page_no < bb->ref_page_no ? -1 : 1);
+	}
+	if (aa->ref_heap_no != bb->ref_heap_no) {
+		return(aa->ref_heap_no < bb->ref_heap_no ? -1 : 1);
+	}
+	if (aa->ref_field_no != bb->ref_field_no) {
+		return(aa->ref_field_no < bb->ref_field_no ? -1 : 1);
+	}
+	return(0);
+}
+
+/**************************************************************//**
+Add a reference to an off-page column to the index->blobs map. */
+UNIV_INTERN
+void
+btr_blob_dbg_add_blob(
+/*==================*/
+	const rec_t*	rec,		/*!< in: clustered index record */
+	ulint		field_no,	/*!< in: off-page column number */
+	ulint		page_no,	/*!< in: start page of the column */
+	dict_index_t*	index,		/*!< in/out: index tree */
+	const char*	ctx)		/*!< in: context (for logging) */
+{
+	btr_blob_dbg_t	b;
+	const page_t*	page	= page_align(rec);
+
+	ut_a(index->blobs);
+
+	b.blob_page_no = page_no;
+	b.ref_page_no = page_get_page_no(page);
+	b.ref_heap_no = page_rec_get_heap_no(rec);
+	b.ref_field_no = field_no;
+	ut_a(b.ref_field_no >= index->n_uniq);
+	b.always_owner = b.owner = TRUE;
+	b.del = FALSE;
+	ut_a(!rec_get_deleted_flag(rec, page_is_comp(page)));
+	btr_blob_dbg_rbt_insert(index, &b, ctx);
+}
+
+/**************************************************************//**
+Add to index->blobs any references to off-page columns from a record.
+@return number of references added */
+UNIV_INTERN
+ulint
+btr_blob_dbg_add_rec(
+/*=================*/
+	const rec_t*	rec,	/*!< in: record */
+	dict_index_t*	index,	/*!< in/out: index */
+	const ulint*	offsets,/*!< in: offsets */
+	const char*	ctx)	/*!< in: context (for logging) */
+{
+	ulint		count	= 0;
+	ulint		i;
+	btr_blob_dbg_t	b;
+	ibool		del;
+
+	ut_ad(rec_offs_validate(rec, index, offsets));
+
+	if (!rec_offs_any_extern(offsets)) {
+		return(0);
+	}
+
+	b.ref_page_no = page_get_page_no(page_align(rec));
+	b.ref_heap_no = page_rec_get_heap_no(rec);
+	del = (rec_get_deleted_flag(rec, rec_offs_comp(offsets)) != 0);
+
+	for (i = 0; i < rec_offs_n_fields(offsets); i++) {
+		if (rec_offs_nth_extern(offsets, i)) {
+			ulint		len;
+			const byte*	field_ref = rec_get_nth_field(
+				rec, offsets, i, &len);
+
+			ut_a(len != UNIV_SQL_NULL);
+			ut_a(len >= BTR_EXTERN_FIELD_REF_SIZE);
+			field_ref += len - BTR_EXTERN_FIELD_REF_SIZE;
+
+			if (!memcmp(field_ref, field_ref_zero,
+				    BTR_EXTERN_FIELD_REF_SIZE)) {
+				/* the column has not been stored yet */
+				continue;
+			}
+
+			b.ref_field_no = i;
+			b.blob_page_no = mach_read_from_4(
+				field_ref + BTR_EXTERN_PAGE_NO);
+			ut_a(b.ref_field_no >= index->n_uniq);
+			b.always_owner = b.owner
+				= !(field_ref[BTR_EXTERN_LEN]
+				    & BTR_EXTERN_OWNER_FLAG);
+			b.del = del;
+
+			btr_blob_dbg_rbt_insert(index, &b, ctx);
+			count++;
+		}
+	}
+
+	return(count);
+}
+
+/**************************************************************//**
+Display the references to off-page columns.
+This function is to be called from a debugger,
+for example when a breakpoint on ut_dbg_assertion_failed is hit. */
+UNIV_INTERN
+void
+btr_blob_dbg_print(
+/*===============*/
+	const dict_index_t*	index)	/*!< in: index tree */
+{
+	const ib_rbt_node_t*	node;
+
+	if (!index->blobs) {
+		return;
+	}
+
+	/* We intentionally do not acquire index->blobs_mutex here.
+	This function is to be called from a debugger, and the caller
+	should make sure that the index->blobs_mutex is held. */
+
+	for (node = rbt_first(index->blobs);
+	     node != NULL; node = rbt_next(index->blobs, node)) {
+		const btr_blob_dbg_t*	b
+			= rbt_value(btr_blob_dbg_t, node);
+		fprintf(stderr, "%u:%u:%u->%u%s%s%s\n",
+			b->ref_page_no, b->ref_heap_no, b->ref_field_no,
+			b->blob_page_no,
+			b->owner ? "" : "(disowned)",
+			b->always_owner ? "" : "(has disowned)",
+			b->del ? "(deleted)" : "");
+	}
+}
+
+/**************************************************************//**
+Remove from index->blobs any references to off-page columns from a record.
+@return number of references removed */
+UNIV_INTERN
+ulint
+btr_blob_dbg_remove_rec(
+/*====================*/
+	const rec_t*	rec,	/*!< in: record */
+	dict_index_t*	index,	/*!< in/out: index */
+	const ulint*	offsets,/*!< in: offsets */
+	const char*	ctx)	/*!< in: context (for logging) */
+{
+	ulint		i;
+	ulint		count	= 0;
+	btr_blob_dbg_t	b;
+
+	ut_ad(rec_offs_validate(rec, index, offsets));
+
+	if (!rec_offs_any_extern(offsets)) {
+		return(0);
+	}
+
+	b.ref_page_no = page_get_page_no(page_align(rec));
+	b.ref_heap_no = page_rec_get_heap_no(rec);
+
+	for (i = 0; i < rec_offs_n_fields(offsets); i++) {
+		if (rec_offs_nth_extern(offsets, i)) {
+			ulint		len;
+			const byte*	field_ref = rec_get_nth_field(
+				rec, offsets, i, &len);
+
+			ut_a(len != UNIV_SQL_NULL);
+			ut_a(len >= BTR_EXTERN_FIELD_REF_SIZE);
+			field_ref += len - BTR_EXTERN_FIELD_REF_SIZE;
+
+			b.ref_field_no = i;
+			b.blob_page_no = mach_read_from_4(
+				field_ref + BTR_EXTERN_PAGE_NO);
+
+			switch (b.blob_page_no) {
+			case 0:
+				/* The column has not been stored yet.
+				The BLOB pointer must be all zero.
+				There cannot be a BLOB starting at
+				page 0, because page 0 is reserved for
+				the tablespace header. */
+				ut_a(!memcmp(field_ref, field_ref_zero,
+					     BTR_EXTERN_FIELD_REF_SIZE));
+				/* fall through */
+			case FIL_NULL:
+				/* the column has been freed already */
+				continue;
+			}
+
+			btr_blob_dbg_rbt_delete(index, &b, ctx);
+			count++;
+		}
+	}
+
+	return(count);
+}
+
+/**************************************************************//**
+Check that there are no references to off-page columns from or to
+the given page. Invoked when freeing or clearing a page.
+@return TRUE when no orphan references exist */
+UNIV_INTERN
+ibool
+btr_blob_dbg_is_empty(
+/*==================*/
+	dict_index_t*	index,		/*!< in: index */
+	ulint		page_no)	/*!< in: page number */
+{
+	const ib_rbt_node_t*	node;
+	ibool			success	= TRUE;
+
+	if (!index->blobs) {
+		return(success);
+	}
+
+	mutex_enter(&index->blobs_mutex);
+
+	for (node = rbt_first(index->blobs);
+	     node != NULL; node = rbt_next(index->blobs, node)) {
+		const btr_blob_dbg_t*	b
+			= rbt_value(btr_blob_dbg_t, node);
+
+		if (b->ref_page_no != page_no && b->blob_page_no != page_no) {
+			continue;
+		}
+
+		fprintf(stderr,
+			"InnoDB: orphan BLOB ref%s%s%s %u:%u:%u->%u\n",
+			b->owner ? "" : "(disowned)",
+			b->always_owner ? "" : "(has disowned)",
+			b->del ? "(deleted)" : "",
+			b->ref_page_no, b->ref_heap_no, b->ref_field_no,
+			b->blob_page_no);
+
+		if (b->blob_page_no != page_no || b->owner || !b->del) {
+			success = FALSE;
+		}
+	}
+
+	mutex_exit(&index->blobs_mutex);
+	return(success);
+}
+
+/**************************************************************//**
+Count and process all references to off-page columns on a page.
+@return number of references processed */
+UNIV_INTERN
+ulint
+btr_blob_dbg_op(
+/*============*/
+	const page_t*		page,	/*!< in: B-tree leaf page */
+	const rec_t*		rec,	/*!< in: record to start from
+					(NULL to process the whole page) */
+	dict_index_t*		index,	/*!< in/out: index */
+	const char*		ctx,	/*!< in: context (for logging) */
+	const btr_blob_dbg_op_f	op)	/*!< in: operation on records */
+{
+	ulint		count	= 0;
+	mem_heap_t*	heap	= NULL;
+	ulint		offsets_[REC_OFFS_NORMAL_SIZE];
+	ulint*		offsets	= offsets_;
+	rec_offs_init(offsets_);
+
+	ut_a(fil_page_get_type(page) == FIL_PAGE_INDEX);
+	ut_a(!rec || page_align(rec) == page);
+
+	if (!index->blobs || !page_is_leaf(page)
+	    || !dict_index_is_clust(index)) {
+		return(0);
+	}
+
+	if (rec == NULL) {
+		rec = page_get_infimum_rec(page);
+	}
+
+	do {
+		offsets = rec_get_offsets(rec, index, offsets,
+					  ULINT_UNDEFINED, &heap);
+		count += op(rec, index, offsets, ctx);
+		rec = page_rec_get_next_const(rec);
+	} while (!page_rec_is_supremum(rec));
+
+	if (UNIV_LIKELY_NULL(heap)) {
+		mem_heap_free(heap);
+	}
+
+	return(count);
+}
+
+/**************************************************************//**
+Count and add to index->blobs any references to off-page columns
+from records on a page.
+@return number of references added */
+UNIV_INTERN
+ulint
+btr_blob_dbg_add(
+/*=============*/
+	const page_t*	page,	/*!< in: rewritten page */
+	dict_index_t*	index,	/*!< in/out: index */
+	const char*	ctx)	/*!< in: context (for logging) */
+{
+	btr_blob_dbg_assert_empty(index, page_get_page_no(page));
+
+	return(btr_blob_dbg_op(page, NULL, index, ctx, btr_blob_dbg_add_rec));
+}
+
+/**************************************************************//**
+Count and remove from index->blobs any references to off-page columns
+from records on a page.
+Used when reorganizing a page, before copying the records.
+@return number of references removed */
+UNIV_INTERN
+ulint
+btr_blob_dbg_remove(
+/*================*/
+	const page_t*	page,	/*!< in: b-tree page */
+	dict_index_t*	index,	/*!< in/out: index */
+	const char*	ctx)	/*!< in: context (for logging) */
+{
+	ulint	count;
+
+	count = btr_blob_dbg_op(page, NULL, index, ctx,
+				btr_blob_dbg_remove_rec);
+
+	/* Check that no references exist. */
+	btr_blob_dbg_assert_empty(index, page_get_page_no(page));
+
+	return(count);
+}
+
+/**************************************************************//**
+Restore in index->blobs any references to off-page columns
+Used when page reorganize fails due to compressed page overflow. */
+UNIV_INTERN
+void
+btr_blob_dbg_restore(
+/*=================*/
+	const page_t*	npage,	/*!< in: page that failed to compress  */
+	const page_t*	page,	/*!< in: copy of original page */
+	dict_index_t*	index,	/*!< in/out: index */
+	const char*	ctx)	/*!< in: context (for logging) */
+{
+	ulint	removed;
+	ulint	added;
+
+	ut_a(page_get_page_no(npage) == page_get_page_no(page));
+	ut_a(page_get_space_id(npage) == page_get_space_id(page));
+
+	removed = btr_blob_dbg_remove(npage, index, ctx);
+	added = btr_blob_dbg_add(page, index, ctx);
+	ut_a(added == removed);
+}
+
+/**************************************************************//**
+Modify the 'deleted' flag of a record. */
+UNIV_INTERN
+void
+btr_blob_dbg_set_deleted_flag(
+/*==========================*/
+	const rec_t*		rec,	/*!< in: record */
+	dict_index_t*		index,	/*!< in/out: index */
+	const ulint*		offsets,/*!< in: rec_get_offs(rec, index) */
+	ibool			del)	/*!< in: TRUE=deleted, FALSE=exists */
+{
+	const ib_rbt_node_t*	node;
+	btr_blob_dbg_t		b;
+	btr_blob_dbg_t*		c;
+	ulint			i;
+
+	ut_ad(rec_offs_validate(rec, index, offsets));
+	ut_a(dict_index_is_clust(index));
+	ut_a(del == !!del);/* must be FALSE==0 or TRUE==1 */
+
+	if (!rec_offs_any_extern(offsets) || !index->blobs) {
+
+		return;
+	}
+
+	b.ref_page_no = page_get_page_no(page_align(rec));
+	b.ref_heap_no = page_rec_get_heap_no(rec);
+
+	for (i = 0; i < rec_offs_n_fields(offsets); i++) {
+		if (rec_offs_nth_extern(offsets, i)) {
+			ulint		len;
+			const byte*	field_ref = rec_get_nth_field(
+				rec, offsets, i, &len);
+
+			ut_a(len != UNIV_SQL_NULL);
+			ut_a(len >= BTR_EXTERN_FIELD_REF_SIZE);
+			field_ref += len - BTR_EXTERN_FIELD_REF_SIZE;
+
+			b.ref_field_no = i;
+			b.blob_page_no = mach_read_from_4(
+				field_ref + BTR_EXTERN_PAGE_NO);
+
+			switch (b.blob_page_no) {
+			case 0:
+				ut_a(memcmp(field_ref, field_ref_zero,
+					    BTR_EXTERN_FIELD_REF_SIZE));
+				/* page number 0 is for the
+				page allocation bitmap */
+			case FIL_NULL:
+				/* the column has been freed already */
+				ut_error;
+			}
+
+			mutex_enter(&index->blobs_mutex);
+			node = rbt_lookup(index->blobs, &b);
+			ut_a(node);
+
+			c = rbt_value(btr_blob_dbg_t, node);
+			/* The flag should be modified. */
+			c->del = del;
+			if (btr_blob_dbg_msg) {
+				b = *c;
+				mutex_exit(&index->blobs_mutex);
+				btr_blob_dbg_msg_issue("del_mk", &b, "");
+			} else {
+				mutex_exit(&index->blobs_mutex);
+			}
+		}
+	}
+}
+
+/**************************************************************//**
+Change the ownership of an off-page column. */
+UNIV_INTERN
+void
+btr_blob_dbg_owner(
+/*===============*/
+	const rec_t*		rec,	/*!< in: record */
+	dict_index_t*		index,	/*!< in/out: index */
+	const ulint*		offsets,/*!< in: rec_get_offs(rec, index) */
+	ulint			i,	/*!< in: ith field in rec */
+	ibool			own)	/*!< in: TRUE=owned, FALSE=disowned */
+{
+	const ib_rbt_node_t*	node;
+	btr_blob_dbg_t		b;
+	const byte*		field_ref;
+	ulint			len;
+
+	ut_ad(rec_offs_validate(rec, index, offsets));
+	ut_a(rec_offs_nth_extern(offsets, i));
+
+	field_ref = rec_get_nth_field(rec, offsets, i, &len);
+	ut_a(len != UNIV_SQL_NULL);
+	ut_a(len >= BTR_EXTERN_FIELD_REF_SIZE);
+	field_ref += len - BTR_EXTERN_FIELD_REF_SIZE;
+
+	b.ref_page_no = page_get_page_no(page_align(rec));
+	b.ref_heap_no = page_rec_get_heap_no(rec);
+	b.ref_field_no = i;
+	b.owner = !(field_ref[BTR_EXTERN_LEN] & BTR_EXTERN_OWNER_FLAG);
+	b.blob_page_no = mach_read_from_4(field_ref + BTR_EXTERN_PAGE_NO);
+
+	ut_a(b.owner == own);
+
+	mutex_enter(&index->blobs_mutex);
+	node = rbt_lookup(index->blobs, &b);
+	/* row_ins_clust_index_entry_by_modify() invokes
+	btr_cur_unmark_extern_fields() also for the newly inserted
+	references, which are all zero bytes until the columns are stored.
+	The node lookup must fail if and only if that is the case. */
+	ut_a(!memcmp(field_ref, field_ref_zero, BTR_EXTERN_FIELD_REF_SIZE)
+	     == !node);
+
+	if (node) {
+		btr_blob_dbg_t*	c = rbt_value(btr_blob_dbg_t, node);
+		/* Some code sets ownership from TRUE to TRUE.
+		We do not allow changing ownership from FALSE to FALSE. */
+		ut_a(own || c->owner);
+
+		c->owner = own;
+		if (!own) {
+			c->always_owner = FALSE;
+		}
+	}
+
+	mutex_exit(&index->blobs_mutex);
+}
+#endif /* UNIV_BLOB_DEBUG */
+
 /*
 Latching strategy of the InnoDB B-tree
 --------------------------------------
@@ -289,7 +843,7 @@ btr_get_next_user_rec(
 /**************************************************************//**
 Creates a new index page (not the root, and also not
 used in page reorganization).  @see btr_page_empty(). */
-static
+UNIV_INTERN
 void
 btr_page_create(
 /*============*/
@@ -302,6 +856,7 @@ btr_page_create(
 	page_t*		page = buf_block_get_frame(block);
 
 	ut_ad(mtr_memo_contains(mtr, block, MTR_MEMO_PAGE_X_FIX));
+	btr_blob_dbg_assert_empty(index, buf_block_get_page_no(block));
 
 	if (UNIV_LIKELY_NULL(page_zip)) {
 		page_create_zip(block, index, level, mtr);
@@ -501,6 +1056,7 @@ btr_page_free_low(
 	modify clock */
 
 	buf_block_modify_clock_inc(block);
+	btr_blob_dbg_assert_empty(index, buf_block_get_page_no(block));
 
 	if (dict_index_is_ibuf(index)) {
 
@@ -785,6 +1341,13 @@ btr_create(
 		block = buf_page_get(space, zip_size, page_no,
 				     RW_X_LATCH, mtr);
 	} else {
+#ifdef UNIV_BLOB_DEBUG
+		if ((type & DICT_CLUSTERED) && !index->blobs) {
+			mutex_create(&index->blobs_mutex, SYNC_ANY_LATCH);
+			index->blobs = rbt_create(sizeof(btr_blob_dbg_t),
+						  btr_blob_dbg_cmp);
+		}
+#endif /* UNIV_BLOB_DEBUG */
 		block = fseg_create(space, 0,
 				    PAGE_HEADER + PAGE_BTR_SEG_TOP, mtr);
 	}
@@ -1026,6 +1589,7 @@ btr_page_reorganize_low(
 
 	block->check_index_page_at_flush = TRUE;
 #endif /* !UNIV_HOTBACKUP */
+	btr_blob_dbg_remove(page, index, "btr_page_reorganize");
 
 	/* Recreate the page: note that global data on page (possible
 	segment headers, next page-field, etc.) is preserved intact */
@@ -1054,6 +1618,8 @@ btr_page_reorganize_low(
 	    (!page_zip_compress(page_zip, page, index, NULL))) {
 
 		/* Restore the old page and exit. */
+		btr_blob_dbg_restore(page, temp_page, index,
+				     "btr_page_reorganize_compress_fail");
 
 #if defined UNIV_DEBUG || defined UNIV_ZIP_DEBUG
 		/* Check that the bytes that we skip are identical. */
@@ -1168,7 +1734,7 @@ btr_parse_page_reorganize(
 #ifndef UNIV_HOTBACKUP
 /*************************************************************//**
 Empties an index page.  @see btr_page_create(). */
-static
+UNIV_INTERN
 void
 btr_page_empty(
 /*===========*/
@@ -1187,6 +1753,7 @@ btr_page_empty(
 #endif /* UNIV_ZIP_DEBUG */
 
 	btr_search_drop_page_hash_index(block);
+	btr_blob_dbg_remove(page, index, "btr_page_empty");
 
 	/* Recreate the page: note that global data on page (possible
 	segment headers, next page-field, etc.) is preserved intact */
@@ -1729,13 +2296,13 @@ btr_insert_on_non_leaf_level_func(
 /**************************************************************//**
 Attaches the halves of an index page on the appropriate level in an
 index tree. */
-static
+UNIV_INTERN
 void
 btr_attach_half_pages(
 /*==================*/
 	dict_index_t*	index,		/*!< in: the index tree */
 	buf_block_t*	block,		/*!< in/out: page to be split */
-	rec_t*		split_rec,	/*!< in: first record on upper
+	const rec_t*	split_rec,	/*!< in: first record on upper
 					half page */
 	buf_block_t*	new_block,	/*!< in/out: the new half page */
 	ulint		direction,	/*!< in: FSP_UP or FSP_DOWN */
@@ -2427,15 +2994,16 @@ btr_node_ptr_delete(
 	ut_a(err == DB_SUCCESS);
 
 	if (!compressed) {
-		btr_cur_compress_if_useful(&cursor, mtr);
+		btr_cur_compress_if_useful(&cursor, FALSE, mtr);
 	}
 }
 
 /*************************************************************//**
 If page is the only on its level, this function moves its records to the
-father page, thus reducing the tree height. */
+father page, thus reducing the tree height.
+@return father block */
 static
-void
+buf_block_t*
 btr_lift_page_up(
 /*=============*/
 	dict_index_t*	index,	/*!< in: index tree */
@@ -2527,6 +3095,7 @@ btr_lift_page_up(
 						       index);
 	}
 
+	btr_blob_dbg_remove(page, index, "btr_lift_page_up");
 	lock_update_copy_and_discard(father_block, block);
 
 	/* Go upward to root page, decrementing levels by one. */
@@ -2551,6 +3120,8 @@ btr_lift_page_up(
 	}
 	ut_ad(page_validate(father_page, index));
 	ut_ad(btr_check_node_ptr(index, father_block, mtr));
+
+	return(father_block);
 }
 
 /*************************************************************//**
@@ -2567,11 +3138,13 @@ UNIV_INTERN
 ibool
 btr_compress(
 /*=========*/
-	btr_cur_t*	cursor,	/*!< in: cursor on the page to merge or lift;
-				the page must not be empty: in record delete
-				use btr_discard_page if the page would become
-				empty */
-	mtr_t*		mtr)	/*!< in: mtr */
+	btr_cur_t*	cursor,	/*!< in/out: cursor on the page to merge
+				or lift; the page must not be empty:
+				when deleting records, use btr_discard_page()
+				if the page would become empty */
+	ibool		adjust,	/*!< in: TRUE if should adjust the
+				cursor position even if compression occurs */
+	mtr_t*		mtr)	/*!< in/out: mini-transaction */
 {
 	dict_index_t*	index;
 	ulint		space;
@@ -2589,12 +3162,14 @@ btr_compress(
 	ulint*		offsets;
 	ulint		data_size;
 	ulint		n_recs;
+	ulint		nth_rec = 0; /* remove bogus warning */
 	ulint		max_ins_size;
 	ulint		max_ins_size_reorg;
 
 	block = btr_cur_get_block(cursor);
 	page = btr_cur_get_page(cursor);
 	index = btr_cur_get_index(cursor);
+
 	ut_a((ibool) !!page_is_comp(page) == dict_table_is_comp(index->table));
 
 	ut_ad(mtr_memo_contains(mtr, dict_index_get_lock(index),
@@ -2615,6 +3190,10 @@ btr_compress(
 	offsets = btr_page_get_father_block(NULL, heap, index, block, mtr,
 					    &father_cursor);
 
+	if (adjust) {
+		nth_rec = page_rec_get_n_recs_before(btr_cur_get_rec(cursor));
+	}
+
 	/* Decide the page to which we try to merge and which will inherit
 	the locks */
 
@@ -2641,9 +3220,9 @@ btr_compress(
 	} else {
 		/* The page is the only one on the level, lift the records
 		to the father */
-		btr_lift_page_up(index, block, mtr);
-		mem_heap_free(heap);
-		return(TRUE);
+
+		merge_block = btr_lift_page_up(index, block, mtr);
+		goto func_exit;
 	}
 
 	n_recs = page_get_n_recs(page);
@@ -2725,6 +3304,10 @@ err_exit:
 
 		btr_node_ptr_delete(index, block, mtr);
 		lock_update_merge_left(merge_block, orig_pred, block);
+
+		if (adjust) {
+			nth_rec += page_rec_get_n_recs_before(orig_pred);
+		}
 	} else {
 		rec_t*		orig_succ;
 #ifdef UNIV_BTR_DEBUG
@@ -2788,7 +3371,7 @@ err_exit:
 		lock_update_merge_right(merge_block, orig_succ, block);
 	}
 
-	mem_heap_free(heap);
+	btr_blob_dbg_remove(page, index, "btr_compress");
 
 	if (!dict_index_is_clust(index) && page_is_leaf(merge_page)) {
 		/* Update the free bits of the B-tree page in the
@@ -2840,6 +3423,16 @@ err_exit:
 	btr_page_free(index, block, mtr);
 
 	ut_ad(btr_check_node_ptr(index, merge_block, mtr));
+func_exit:
+	mem_heap_free(heap);
+
+	if (adjust) {
+		btr_cur_position(
+			index,
+			page_rec_get_nth(merge_block->frame, nth_rec),
+			merge_block, cursor);
+	}
+
 	return(TRUE);
 }
 
@@ -3018,6 +3611,8 @@ btr_discard_page(
 				    block);
 	}
 
+	btr_blob_dbg_remove(page, index, "btr_discard_page");
+
 	/* Free the file page */
 	btr_page_free(index, block, mtr);