for more accurate Valgrind debugging.

univ.i: Introduce UNIV_DEBUG_VALGRIND, UNIV_MEM_VALID, and UNIV_MEM_INVALID.

buf_LRU_block_free_non_file_page(): Invalidate the buffer frame
with UNIV_MEM_INVALID().

buf_LRU_get_free_block(): Declare the buffer frame valid
with UNIV_MEM_VALID().

Other memory is allocated and deallocated via malloc() and free(),
which are already overridden by Valgrind.  Without the added
instrumentation, accesses to free pages in the buffer pool cannot
be caught.

The diagnostics could probably be improved further by declaring all
non-latched buffer frames invalid.

rec_convert_dtuple_to_rec_old(): Initialize the record in order to avoid
bogus Valgrind warnings about the ut_ad() in mach_write_to_1() and
mach_write_to_2().

page_zip_compress(), page_zip_write_rec(), page_zip_write_blob_ptr():
Replace ut_ad(page_validate(...)) with ut_ad(page_simple_validate_new(...)),
because otherwise crash recovery would fail.

Make page_zip->data point to an address different from page,
to avoid calling memcpy() with overlapping source and destination.

Identify DB_TRX_ID and DB_ROLL_PTR in the index.

on the ZIP_DUMMY index.  Because it does not contain valid collation
information, the ordering check in page_validate() may fail on pages
containing non-binary data.

Instead, let the callers of page_zip_decompress() invoke page_validate()
when the index information is available.

"next BLOB page" pointer, write it also to the compressed page,
which is the one that will be flushed to disk.

unexpected end of compressed BLOB.

reporting and handling of inflate() errors.

always convert back big_rec_vec.

was accidentally omitted in r766.

of externally stored columns to 108 bytes when possible.

This will unmask a bug in the handling of BLOBs on compressed tablespaces,
especially of small page sizes.  Apparently, the locally stored part must
be less than 235 bytes in size for the bug to occur.

dict_col_struct: Add field min_prefix.

dict_index_build_internal_non_clust(): Adjust min_prefix.

dtuple_convert_big_rec().  This should never happen, though.

as per revisions r763:765.

old value of PAGE_N_RECS.

page_zip_dir_find_free_low(): Rename to page_zip_dir_find_low().

page_zip_dir_find(): Make use of page_zip_dir_find_low().

of non-clustered indexes.  On these pages, only the bytes rec[-5..-1]
will be omitted from the compressed data stream.  Save time by not looking
for trx_id or externally stored columns.

externally stored columns.  Make some use of the fact in compression and
decompression.

rec_init_offsets(): Add ut_ad(dict_index_is_clust(index)) before flagging
external columns.

page_zip_get_trailer_len(): Assert ut_ad(!page_zip->n_blobs) unless
dict_index_is_clust(index).

page_zip_get_n_prev_extern(): Add ut_ad(dict_index_is_clust(index)).

page_zip_compress(), page_zip_decompress_low(): Add dict_index_is_clust()
assertions.  Allow completely external storage of columns.  Simplify
the computation of "externs".

page_zip_write_rec(): Store leaf node records of non-clustered indexes
with one memcpy(), avoiding rec_offs_n_extern() and the for loop.

page_zip_write_blob_ptr(): Add ut_ad(dict_index_is_clust(index)).
Simplify the computation of "externs".

page_zip_clear_rec(): Only attempt to zero out BLOB pointers when
the record belongs to a leaf page of a clustered index.

page_zip_dir_delete(): Take a fast path when the record is
not on a leaf page of a clustered index.
Simplify the computation of "externs".

page_zip_copy(): Assert that n_blobs is zero on anything else than
leaf pages of clustered indexes.

if and only if the records on the page contain a trx_id column.
(Dummy indexes of non-leaf pages will always show up as non-clustered.)

referencing it, to prevent a ut_ad() assertion on page_zip_get_trailer_len()
from failing.  Promote that assertion to ut_a().

of secondary indexes.  (This is just an optimization; the logic in the
search loop would never store such records externally.)

with page_zip_dir_insert().  Pass page_zip to rec_set_n_owned_new()
and page_dir_slot_set_n_owned().

page_zip_dir_insert(): New function.  Shift the dense page directory and
write the inserted record there.

data0data.c: Add #include "page0zip.h" that was forgotten from r739.

page_cur_insert_rec_low(): Remove a memory leak when preventing
extra_size to grow.

the record will fit on an empty compressed page.

buf_block_alloc(), buf_block_free(), buf_frame_alloc(), buf_frame_free():
Make inlined.

according to InnoDB formatting rules.

record will fit or need external storage.

btr_page_get_sure_split_rec(): Estimate the free space of an empty
compressed page.

page_zip_rec_needs_ext(): New function, to replace existing tests whether
external storage is needed.

struct mtr_struct: Omit unused field "state" unless #ifdef UNIV_DEBUG.

buf_block_buf_fix_inc_debug(): Remove redundant __attribute__((unused))
and #ifdef UNIV_SYNC_DEBUG.

print functions.

buf_LRU_print(), buf_print(): Replace #ifdef UNIV_DEBUG
with #ifdef UNIV_DEBUG_PRINT.

will compile with inlining disabled.

page0page.h: Add #include "page0zip.h"

page_dir_slot_get_rec(): Avoid void* arithmetics.

trx0undo.ic, trx0sys.ic: Remove unnecessary #include "page0zip.h"

page_zip_write_header(): Move prototype from page0types.h to page0zip.h

"old_end" with "ret".  Otherwise, a page_zip_reorganize() would make
lock_move_rec_list_start() fail.