Bug#45288: pb2 returns a lot of compilation warnings on linux

Fix warnings flagged by the new warning option -Wunused-but-set-variable
that was added to GCC 4.6 and that is enabled by -Wunused and -Wall. The
option causes a warning whenever a local variable is assigned to but is
later unused. It also warns about meaningless pointer dereferences.

client/mysql.cc:
  Meaningless pointer dereferences.
client/mysql_upgrade.c:
  Check whether reading from the file succeeded.
extra/comp_err.c:
  Unused.
extra/yassl/src/yassl_imp.cpp:
  Skip instead of reading data that is discarded.
include/my_pthread.h:
  Variable is only used in debug builds.
include/mysys_err.h:
  Add new error messages.
mysys/errors.c:
  Add new error message for permission related functions.
mysys/mf_iocache.c:
  Variable is only checked under THREAD.
mysys/my_copy.c:
  Raise a error if chmod or chown fails.
mysys/my_redel.c:
  Raise a error if chmod or chown fails.
regex/engine.c:
  Use a equivalent variable for the assert.
server-tools/instance-manager/instance_options.cc:
  Unused.
sql/field.cc:
  Unused.
sql/item.cc:
  Unused.
sql/log.cc:
  Do not ignore the return value of freopen: only set buffer if
  reopening succeeds.
  
  Adjust doxygen comment to the right function.
  
  Pass message lenght to log function.
sql/mysqld.cc:
  Do not ignore the return value of freopen: only set buffer if
  reopening succeeds.
sql/partition_info.cc:
  Unused.
sql/slave.cc:
  No need to set pointer to the address of '\0'.
sql/spatial.cc:
  Unused. Left for historical purposes.
sql/sql_acl.cc:
  Unused.
sql/sql_base.cc:
  Pointers are always set to the same variables.
sql/sql_parse.cc:
  End statement if reading fails.
  
  Store the buffer after it has actually been updated.
sql/sql_repl.cc:
  No need to set pointer to the address of '\0'.
sql/sql_show.cc:
  Put variable under the same ifdef block.
sql/udf_example.c:
  Set null pointer flag appropriately.
storage/csv/ha_tina.cc:
  Meaningless dereferences.
storage/example/ha_example.cc:
  Return the error since it's available.
storage/myisam/mi_locking.c:
  Remove unused and dead code.

1 files changed, 0 insertions, 3 deletions

diff --git a/storage/myisam/rt_split.c b/storage/myisam/rt_split.c
index 88cf643faf9..03d22de68fa 100644
--- a/storage/myisam/rt_split.c
+++ b/storage/myisam/rt_split.c
@@ -255,7 +255,6 @@ int rtree_split_page(MI_INFO *info, MI_KEYDEF *keyinfo, uchar *page, uchar *key,
   SplitStruct *stop;
   double *coord_buf;
   double *next_coord;
-  double *old_coord;
   int n_dim;
   uchar *source_cur, *cur1, *cur2;
   uchar *new_page= info->buff;
@@ -293,8 +292,6 @@ int rtree_split_page(MI_INFO *info, MI_KEYDEF *keyinfo, uchar *page, uchar *key,
   rtree_d_mbr(keyinfo->seg, key, key_length, cur->coords);
   cur->key = key;
 
-  old_coord = next_coord;
-
   if (split_rtree_node(task, max_keys + 1,
        mi_getint(page) + full_length + 2, full_length, 
        rt_PAGE_MIN_SIZE(keyinfo->block_length),