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, 5 deletions

diff --git a/storage/myisammrg/myrg_open.c b/storage/myisammrg/myrg_open.c
index 5fcbe0c3297..18f8aa8d2c0 100644
--- a/storage/myisammrg/myrg_open.c
+++ b/storage/myisammrg/myrg_open.c
@@ -227,9 +227,7 @@ MYRG_INFO *myrg_parent_open(const char *parent_name,
   int       save_errno;
   int       insert_method;
   uint      length;
-  uint      dir_length;
   uint      child_count;
-  size_t    name_buff_length;
   File      fd;
   IO_CACHE  file_cache;
   char      parent_name_buff[FN_REFLEN * 2];
@@ -299,7 +297,6 @@ MYRG_INFO *myrg_parent_open(const char *parent_name,
   }
 
   /* Call callback for each child. */
-  dir_length= dirname_part(parent_name_buff, parent_name, &name_buff_length);
   my_b_seek(&file_cache, 0);
   while ((length= my_b_gets(&file_cache, child_name_buff, FN_REFLEN - 1)))
   {
@@ -379,7 +376,6 @@ int myrg_attach_children(MYRG_INFO *m_info, int handle_locking,
 {
   ulonglong  file_offset;
   MI_INFO    *myisam;
-  int        rc;
   int        errpos;
   int        save_errno;
   uint       idx;
@@ -398,7 +394,6 @@ int myrg_attach_children(MYRG_INFO *m_info, int handle_locking,
     here and in ha_myisammrg::store_lock() forces consistent data.
   */
   pthread_mutex_lock(&m_info->mutex);
-  rc= 1;
   errpos= 0;
   file_offset= 0;
   min_keys= 0;