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, 18 insertions, 6 deletions

diff --git a/mysys/my_redel.c b/mysys/my_redel.c
index 6521253f949..4013c5c8323 100644
--- a/mysys/my_redel.c
+++ b/mysys/my_redel.c
@@ -76,11 +76,8 @@ end:
 int my_copystat(const char *from, const char *to, int MyFlags)
 {
   struct stat statbuf;
-#if !defined(__WIN__) && !defined(__NETWARE__)
-  int res;
-#endif
 
-  if (stat((char*) from, &statbuf))
+  if (stat(from, &statbuf))
   {
     my_errno=errno;
     if (MyFlags & (MY_FAE+MY_WME))
@@ -89,7 +86,15 @@ int my_copystat(const char *from, const char *to, int MyFlags)
   }
   if ((statbuf.st_mode & S_IFMT) != S_IFREG)
     return 1;
-  VOID(chmod(to, statbuf.st_mode & 07777));		/* Copy modes */
+
+  /* Copy modes */
+  if (chmod(to, statbuf.st_mode & 07777))
+  {
+    my_errno= errno;
+    if (MyFlags & (MY_FAE+MY_WME))
+      my_error(EE_CHANGE_PERMISSIONS, MYF(ME_BELL+ME_WAITTANG), from, errno);
+    return -1;
+  }
 
 #if !defined(__WIN__) && !defined(__NETWARE__)
   if (statbuf.st_nlink > 1 && MyFlags & MY_LINK_WARNING)
@@ -97,7 +102,14 @@ int my_copystat(const char *from, const char *to, int MyFlags)
     if (MyFlags & MY_LINK_WARNING)
       my_error(EE_LINK_WARNING,MYF(ME_BELL+ME_WAITTANG),from,statbuf.st_nlink);
   }
-  res= chown(to, statbuf.st_uid, statbuf.st_gid);	/* Copy ownership */
+  /* Copy ownership */
+  if (chown(to, statbuf.st_uid, statbuf.st_gid))
+  {
+    my_errno= errno;
+    if (MyFlags & (MY_FAE+MY_WME))
+      my_error(EE_CHANGE_OWNERSHIP, MYF(ME_BELL+ME_WAITTANG), from, errno);
+    return -1;
+  }
 #endif /* !__WIN__ && !__NETWARE__ */
 
 #ifndef VMS