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, 1 insertions, 3 deletions

diff --git a/sql/sql_show.cc b/sql/sql_show.cc
index d0e76e501e2..eb5d3a1965d 100644
--- a/sql/sql_show.cc
+++ b/sql/sql_show.cc
@@ -3868,7 +3868,6 @@ static int get_schema_column_record(THD *thd, TABLE_LIST *tables,
     uint flags=field->flags;
     char tmp[MAX_FIELD_WIDTH];
     String type(tmp,sizeof(tmp), system_charset_info);
-    char *end;
     int decimals, field_length;
 
     if (wild && wild[0] &&
@@ -3889,7 +3888,7 @@ static int get_schema_column_record(THD *thd, TABLE_LIST *tables,
                                  field->field_name) & COL_ACLS;
     if (!tables->schema_table && !col_access)
       continue;
-    end= tmp;
+    char *end= tmp;
     for (uint bitnr=0; col_access ; col_access>>=1,bitnr++)
     {
       if (col_access & 1)
@@ -4015,7 +4014,6 @@ static int get_schema_column_record(THD *thd, TABLE_LIST *tables,
     table->field[15]->store((const char*) pos,
                             strlen((const char*) pos), cs);
 
-    end= tmp;
     if (field->unireg_check == Field::NEXT_NUMBER)
       table->field[16]->store(STRING_WITH_LEN("auto_increment"), cs);
     if (show_table->timestamp_field == field &&