Bug#42733: Type-punning warnings when compiling MySQL --

           strict aliasing violations.

Essentially, the problem is that large parts of the server were
developed in simpler times (last decades, pre C99 standard) when
strict aliasing and compilers supporting such optimizations were
rare to non-existent. Thus, when compiling the server with a modern
compiler that uses strict aliasing rules to perform optimizations,
there are several places in the code that might trigger undefined
behavior.

As evinced by some recent bugs, GCC does a somewhat good of job
misoptimizing such code, but on the other hand also gives warnings
about suspicious code. One problem is that the warnings aren't
always accurate, yet we can't afford to just shut them off as we
might miss real cases. False-positive cases are aggravated mostly
by casts that are likely to trigger undefined behavior.

The solution is to start a cleanup process focused on fixing and
reducing the amount of strict-aliasing related warnings produced
by GCC and others compilers. A good deal of noise reduction can
be achieved by just removing useless casts that are product of
historical cruft and are likely to trigger undefined behavior if
dereferenced.

client/mysql.cc:
  Remove now-unnecessary casts.
  Break up large strings.
client/mysql_upgrade.c:
  Remove now-unnecessary casts.
client/mysqladmin.cc:
  Remove now-unnecessary casts.
  Break up large strings.
client/mysqlbinlog.cc:
  Remove now-unnecessary casts.
client/mysqlcheck.c:
  Remove now-unnecessary casts.
client/mysqldump.c:
  Remove now-unnecessary casts.
client/mysqlimport.c:
  Remove now-unnecessary casts.
client/mysqlshow.c:
  Remove now-unnecessary casts.
client/mysqlslap.c:
  Remove now-unnecessary casts.
client/mysqltest.cc:
  Remove now-unnecessary casts.
extra/comp_err.c:
  Remove now-unnecessary casts.
extra/my_print_defaults.c:
  Remove now-unnecessary casts.
  Break up large strings.
extra/mysql_waitpid.c:
  Remove now-unnecessary casts.
extra/perror.c:
  Remove now-unnecessary casts.
extra/resolve_stack_dump.c:
  Remove now-unnecessary casts.
extra/resolveip.c:
  Remove now-unnecessary casts.
include/my_getopt.h:
  Use a void pointer type as the opaque type to avoid problems with type
  incompatibility -- GCC issues warnings when the type name is not type
  compatible with a operand. As a side bonus, a explicit cast won't be
  necessary anymore.
include/sslopt-longopts.h:
  Remove now-unnecessary casts.
  Break up large strings.
mysys/my_getopt.c:
  Update opaque type and introduce a type definition for the
  argument to my_getopt_register_get_addr.
server-tools/instance-manager/options.cc:
  Remove now-unnecessary casts.
sql/mysqld.cc:
  Remove now-unnecessary casts.
  Break up large strings.
  Update mysql_getopt_value prototype (the old prototype
  was different from the definition anyway).
sql/sql_plugin.cc:
  The type of a pointer to a function must be compatible with the
  pointed-to function type, otherwise the behavior is undefined.
sql/table.cc:
  The variable buf pointer to pointer to pointer to constant char
  could improperly alias a incompatible type in call to fix_type_
  pointers. Since this was actually dead code, it is simply removed.
sql/unireg.cc:
  Remove call to get_form_pos. The code creates a new FRM file which
  is always truncated and writes the form position as 0. Hence, no
  need to retrieve it, we now for sure it is 0.
storage/archive/archive_reader.c:
  Remove now-unnecessary casts.
storage/myisam/ft_nlq_search.c:
  Read weight directly from the buffer.
storage/myisam/fulltext.h:
  Add explanation about the type duality of a key buffer.
  Add accessor macro to retrieve a FT float value.
storage/myisam/mi_test1.c:
  Remove now-unnecessary casts.
storage/myisam/myisam_ftdump.c:
  Read weight directly from the buffer.
storage/myisam/myisamchk.c:
  Remove now-unnecessary casts.
storage/myisam/myisamlog.c:
  A pointer to char was used to alias a pointer to pointer to
  unsigned char, thus violating strict aliasing rules.
storage/myisam/myisampack.c:
  Remove now-unnecessary casts.
strings/decimal.c:
  Remove aliasing violation, printing the value is enough for
  debugging purposes.
tests/mysql_client_test.c:
  Remove now-unnecessary casts.

8 files changed, 79 insertions, 65 deletions

diff --git a/storage/archive/archive_reader.c b/storage/archive/archive_reader.c
index 84d4e318b49..0cf795cefdf 100644
--- a/storage/archive/archive_reader.c
+++ b/storage/archive/archive_reader.c
@@ -355,15 +355,14 @@ static struct my_option my_long_options[] =
    0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
   {"set-auto-increment", 'A',
    "Force auto_increment to start at this or higher value. If no value is given, then sets the next auto_increment value to the highest used value for the auto key + 1.",
-   (uchar**) &new_auto_increment,
-   (uchar**) &new_auto_increment,
+   &new_auto_increment, &new_auto_increment,
    0, GET_ULL, OPT_ARG, 0, 0, 0, 0, 0, 0},
   {"silent", 's',
    "Only print errors. One can use two -s to make archive_reader very silent.",
    0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
   {"tmpdir", 't',
    "Path for temporary files.",
-   (uchar**) &opt_tmpdir,
+   &opt_tmpdir,
    0, 0, GET_STR, REQUIRED_ARG, 0, 0, 0, 0, 0, 0},
   {"version", 'V',
    "Print version and exit.",
diff --git a/storage/myisam/ft_nlq_search.c b/storage/myisam/ft_nlq_search.c
index eb563638d36..5317da78ee4 100644
--- a/storage/myisam/ft_nlq_search.c
+++ b/storage/myisam/ft_nlq_search.c
@@ -123,7 +123,7 @@ static int walk_and_match(FT_WORD *word, uint32 count, ALL_IN_ONE *aio)
       goto do_skip;
     }
 #if HA_FT_WTYPE == HA_KEYTYPE_FLOAT
-    tmp_weight=*(float*)&subkeys;
+    ft_floatXget(tmp_weight, info->lastkey+info->lastkey_length-extra);
 #else
 #error
 #endif
diff --git a/storage/myisam/fulltext.h b/storage/myisam/fulltext.h
index 856e93e034d..853eb6362e6 100644
--- a/storage/myisam/fulltext.h
+++ b/storage/myisam/fulltext.h
@@ -24,8 +24,23 @@
 #define HA_FT_WLEN   4
 #define FT_SEGS      2
 
+/**
+  Accessor methods for the weight and the number of subkeys in a buffer.
+
+  The weight is of float type and subkeys number is of integer type. Both
+  are stored in the same position of the buffer and the stored object is
+  identified by the sign (bit): the weight value is positive whilst the
+  number of subkeys is negative.
+
+  In light of C's strict-aliasing rules, which roughly state that an object
+  must not be accessed through incompatible types, these methods are used to
+  avoid any problems arising from the type duality inside the buffer. The
+  values are retrieved using a character type which can access any object.
+*/
 #define ft_sintXkorr(A)    mi_sint4korr(A)
 #define ft_intXstore(T,A)  mi_int4store(T,A)
+#define ft_floatXget(V,M)  mi_float4get(V,M)
+
 
 extern const HA_KEYSEG ft_keysegs[FT_SEGS];
 
diff --git a/storage/myisam/mi_test1.c b/storage/myisam/mi_test1.c
index f218bf4e77f..363b024737a 100644
--- a/storage/myisam/mi_test1.c
+++ b/storage/myisam/mi_test1.c
@@ -536,21 +536,21 @@ static struct my_option my_long_options[] =
   {"debug", '#', "Undocumented",
    0, 0, 0, GET_STR, REQUIRED_ARG, 0, 0, 0, 0, 0, 0},
 #endif
-  {"delete_rows", 'd', "Undocumented", (uchar**) &remove_count,
-   (uchar**) &remove_count, 0, GET_UINT, REQUIRED_ARG, 1000, 0, 0, 0, 0, 0},
+  {"delete_rows", 'd', "Undocumented", &remove_count,
+   &remove_count, 0, GET_UINT, REQUIRED_ARG, 1000, 0, 0, 0, 0, 0},
   {"help", '?', "Display help and exit",
    0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
-  {"insert_rows", 'i', "Undocumented", (uchar**) &insert_count,
-   (uchar**) &insert_count, 0, GET_UINT, REQUIRED_ARG, 1000, 0, 0, 0, 0, 0},
+  {"insert_rows", 'i', "Undocumented", &insert_count,
+   &insert_count, 0, GET_UINT, REQUIRED_ARG, 1000, 0, 0, 0, 0, 0},
   {"key_alpha", 'a', "Use a key of type HA_KEYTYPE_TEXT",
    0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
   {"key_binary_pack", 'B', "Undocumented",
    0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
   {"key_blob", 'b', "Undocumented",
    0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
-  {"key_cache", 'K', "Undocumented", (uchar**) &key_cacheing,
-   (uchar**) &key_cacheing, 0, GET_BOOL, NO_ARG, 0, 0, 0, 0, 0, 0},
-  {"key_length", 'k', "Undocumented", (uchar**) &key_length, (uchar**) &key_length,
+  {"key_cache", 'K', "Undocumented", &key_cacheing,
+   &key_cacheing, 0, GET_BOOL, NO_ARG, 0, 0, 0, 0, 0, 0},
+  {"key_length", 'k', "Undocumented", &key_length, &key_length,
    0, GET_UINT, REQUIRED_ARG, 6, 0, 0, 0, 0, 0},
   {"key_multiple", 'm', "Undocumented",
    0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
@@ -561,21 +561,21 @@ static struct my_option my_long_options[] =
   {"key_varchar", 'w', "Test VARCHAR keys",
    0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
   {"null_fields", 'N', "Define fields with NULL",
-   (uchar**) &null_fields, (uchar**) &null_fields, 0, GET_BOOL, NO_ARG,
+   &null_fields, &null_fields, 0, GET_BOOL, NO_ARG,
    0, 0, 0, 0, 0, 0},
   {"row_fixed_size", 'S', "Undocumented",
    0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
-  {"row_pointer_size", 'R', "Undocumented", (uchar**) &rec_pointer_size,
-   (uchar**) &rec_pointer_size, 0, GET_INT, REQUIRED_ARG, 0, 0, 0, 0, 0, 0},
+  {"row_pointer_size", 'R', "Undocumented", &rec_pointer_size,
+   &rec_pointer_size, 0, GET_INT, REQUIRED_ARG, 0, 0, 0, 0, 0, 0},
   {"silent", 's', "Undocumented",
-   (uchar**) &silent, (uchar**) &silent, 0, GET_BOOL, NO_ARG, 0, 0, 0, 0, 0, 0},
-  {"skip_update", 'U', "Undocumented", (uchar**) &skip_update,
-   (uchar**) &skip_update, 0, GET_BOOL, NO_ARG, 0, 0, 0, 0, 0, 0},
-  {"unique", 'C', "Undocumented", (uchar**) &opt_unique, (uchar**) &opt_unique, 0,
+   &silent, &silent, 0, GET_BOOL, NO_ARG, 0, 0, 0, 0, 0, 0},
+  {"skip_update", 'U', "Undocumented", &skip_update,
+   &skip_update, 0, GET_BOOL, NO_ARG, 0, 0, 0, 0, 0, 0},
+  {"unique", 'C', "Undocumented", &opt_unique, &opt_unique, 0,
    GET_BOOL, NO_ARG, 0, 0, 0, 0, 0, 0},
-  {"update_rows", 'u', "Undocumented", (uchar**) &update_count,
-   (uchar**) &update_count, 0, GET_UINT, REQUIRED_ARG, 1000, 0, 0, 0, 0, 0},
-  {"verbose", 'v', "Be more verbose", (uchar**) &verbose, (uchar**) &verbose, 0,
+  {"update_rows", 'u', "Undocumented", &update_count,
+   &update_count, 0, GET_UINT, REQUIRED_ARG, 1000, 0, 0, 0, 0, 0},
+  {"verbose", 'v', "Be more verbose", &verbose, &verbose, 0,
    GET_BOOL, NO_ARG, 0, 0, 0, 0, 0, 0},
   {"version", 'V', "Print version number and exit",
    0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
diff --git a/storage/myisam/myisam_ftdump.c b/storage/myisam/myisam_ftdump.c
index 63d954242a0..f1637a7e116 100644
--- a/storage/myisam/myisam_ftdump.c
+++ b/storage/myisam/myisam_ftdump.c
@@ -113,7 +113,7 @@ int main(int argc,char *argv[])
 
     subkeys=ft_sintXkorr(info->lastkey+keylen+1);
     if (subkeys >= 0)
-      weight=*(float*)&subkeys;
+      ft_floatXget(weight, info->lastkey+keylen+1);
 
 #ifdef HAVE_SNPRINTF
     snprintf(buf,MAX_LEN,"%.*s",(int) keylen,info->lastkey+1);
diff --git a/storage/myisam/myisamchk.c b/storage/myisam/myisamchk.c
index 611fb6325c8..96ceb35b3d5 100644
--- a/storage/myisam/myisamchk.c
+++ b/storage/myisam/myisamchk.c
@@ -168,7 +168,7 @@ static struct my_option my_long_options[] =
    0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
   {"character-sets-dir", OPT_CHARSETS_DIR,
    "Directory where character sets are.",
-   (uchar**) &charsets_dir, 0, 0, GET_STR, REQUIRED_ARG, 0, 0, 0, 0, 0, 0},
+   &charsets_dir, 0, 0, GET_STR, REQUIRED_ARG, 0, 0, 0, 0, 0, 0},
   {"check", 'c',
    "Check table for errors.",
    0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
@@ -188,8 +188,8 @@ static struct my_option my_long_options[] =
    0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
   {"data-file-length", 'D',
    "Max length of data file (when recreating data-file when it's full).",
-   (uchar**) &check_param.max_data_file_length,
-   (uchar**) &check_param.max_data_file_length,
+   &check_param.max_data_file_length,
+   &check_param.max_data_file_length,
    0, GET_LL, REQUIRED_ARG, 0, 0, 0, 0, 0, 0},
   {"extend-check", 'e',
    "If used when checking a table, ensure that the table is 100 percent consistent, which will take a long time. If used when repairing a table, try to recover every possible row from the data file. Normally this will also find a lot of garbage rows; Don't use this option with repair if you are not totally desperate.",
@@ -211,13 +211,13 @@ static struct my_option my_long_options[] =
    0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
   {"keys-used", 'k',
    "Tell MyISAM to update only some specific keys. # is a bit mask of which keys to use. This can be used to get faster inserts.",
-   (uchar**) &check_param.keys_in_use,
-   (uchar**) &check_param.keys_in_use,
+   &check_param.keys_in_use,
+   &check_param.keys_in_use,
    0, GET_ULL, REQUIRED_ARG, -1, 0, 0, 0, 0, 0},
   {"max-record-length", OPT_MAX_RECORD_LENGTH,
    "Skip rows bigger than this if myisamchk can't allocate memory to hold it",
-   (uchar**) &check_param.max_record_length,
-   (uchar**) &check_param.max_record_length,
+   &check_param.max_record_length,
+   &check_param.max_record_length,
    0, GET_ULL, REQUIRED_ARG, LONGLONG_MAX, 0, LONGLONG_MAX, 0, 0, 0},
   {"medium-check", 'm',
    "Faster than extend-check, but only finds 99.99% of all errors. Should be good enough for most cases.",
@@ -246,12 +246,12 @@ static struct my_option my_long_options[] =
 #endif
   {"set-auto-increment", 'A',
    "Force auto_increment to start at this or higher value. If no value is given, then sets the next auto_increment value to the highest used value for the auto key + 1.",
-   (uchar**) &check_param.auto_increment_value,
-   (uchar**) &check_param.auto_increment_value,
+   &check_param.auto_increment_value,
+   &check_param.auto_increment_value,
    0, GET_ULL, OPT_ARG, 0, 0, 0, 0, 0, 0},
   {"set-collation", OPT_SET_COLLATION,
    "Change the collation used by the index",
-   (uchar**) &set_collation_name, 0, 0, GET_STR, REQUIRED_ARG, 0, 0, 0, 0, 0, 0},
+   &set_collation_name, 0, 0, GET_STR, REQUIRED_ARG, 0, 0, 0, 0, 0, 0},
   {"set-variable", 'O',
    "Change the value of a variable. Please note that this option is deprecated; you can set variables directly with --variable-name=value.",
    0, 0, 0, GET_STR, REQUIRED_ARG, 0, 0, 0, 0, 0, 0},
@@ -263,12 +263,12 @@ static struct my_option my_long_options[] =
    0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
   {"sort-records", 'R',
    "Sort records according to an index. This makes your data much more localized and may speed up things. (It may be VERY slow to do a sort the first time!)",
-   (uchar**) &check_param.opt_sort_key,
-   (uchar**) &check_param.opt_sort_key,
+   &check_param.opt_sort_key,
+   &check_param.opt_sort_key,
    0, GET_UINT, REQUIRED_ARG, 0, 0, 0, 0, 0, 0},
   {"tmpdir", 't',
    "Path for temporary files.",
-   (uchar**) &opt_tmpdir,
+   &opt_tmpdir,
    0, 0, GET_STR, REQUIRED_ARG, 0, 0, 0, 0, 0, 0},
   {"update-state", 'U',
    "Mark tables as crashed if any errors were found.",
@@ -286,54 +286,54 @@ static struct my_option my_long_options[] =
    "Wait if table is locked.",
    0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
   { "key_buffer_size", OPT_KEY_BUFFER_SIZE, "",
-    (uchar**) &check_param.use_buffers, (uchar**) &check_param.use_buffers, 0,
+    &check_param.use_buffers, &check_param.use_buffers, 0,
     GET_ULL, REQUIRED_ARG, USE_BUFFER_INIT, MALLOC_OVERHEAD,
     SIZE_T_MAX, MALLOC_OVERHEAD,  IO_SIZE, 0},
   { "key_cache_block_size", OPT_KEY_CACHE_BLOCK_SIZE,  "",
-    (uchar**) &opt_key_cache_block_size,
-    (uchar**) &opt_key_cache_block_size, 0,
+    &opt_key_cache_block_size,
+    &opt_key_cache_block_size, 0,
     GET_LONG, REQUIRED_ARG, MI_KEY_BLOCK_LENGTH, MI_MIN_KEY_BLOCK_LENGTH,
     MI_MAX_KEY_BLOCK_LENGTH, 0, MI_MIN_KEY_BLOCK_LENGTH, 0},
   { "myisam_block_size", OPT_MYISAM_BLOCK_SIZE,  "",
-    (uchar**) &opt_myisam_block_size, (uchar**) &opt_myisam_block_size, 0,
+    &opt_myisam_block_size, &opt_myisam_block_size, 0,
     GET_LONG, REQUIRED_ARG, MI_KEY_BLOCK_LENGTH, MI_MIN_KEY_BLOCK_LENGTH,
     MI_MAX_KEY_BLOCK_LENGTH, 0, MI_MIN_KEY_BLOCK_LENGTH, 0},
   { "read_buffer_size", OPT_READ_BUFFER_SIZE, "",
-    (uchar**) &check_param.read_buffer_length,
-    (uchar**) &check_param.read_buffer_length, 0, GET_ULONG, REQUIRED_ARG,
+    &check_param.read_buffer_length,
+    &check_param.read_buffer_length, 0, GET_ULONG, REQUIRED_ARG,
     (long) READ_BUFFER_INIT, (long) MALLOC_OVERHEAD,
     INT_MAX32, (long) MALLOC_OVERHEAD, (long) 1L, 0},
   { "write_buffer_size", OPT_WRITE_BUFFER_SIZE, "",
-    (uchar**) &check_param.write_buffer_length,
-    (uchar**) &check_param.write_buffer_length, 0, GET_ULONG, REQUIRED_ARG,
+    &check_param.write_buffer_length,
+    &check_param.write_buffer_length, 0, GET_ULONG, REQUIRED_ARG,
     (long) READ_BUFFER_INIT, (long) MALLOC_OVERHEAD,
     INT_MAX32, (long) MALLOC_OVERHEAD, (long) 1L, 0},
   { "sort_buffer_size", OPT_SORT_BUFFER_SIZE, "",
-    (uchar**) &check_param.sort_buffer_length,
-    (uchar**) &check_param.sort_buffer_length, 0, GET_ULONG, REQUIRED_ARG,
+    &check_param.sort_buffer_length,
+    &check_param.sort_buffer_length, 0, GET_ULONG, REQUIRED_ARG,
     (long) SORT_BUFFER_INIT, (long) (MIN_SORT_BUFFER + MALLOC_OVERHEAD),
     ULONG_MAX, (long) MALLOC_OVERHEAD, (long) 1L, 0},
   { "sort_key_blocks", OPT_SORT_KEY_BLOCKS, "",
-    (uchar**) &check_param.sort_key_blocks,
-    (uchar**) &check_param.sort_key_blocks, 0, GET_ULONG, REQUIRED_ARG,
+    &check_param.sort_key_blocks,
+    &check_param.sort_key_blocks, 0, GET_ULONG, REQUIRED_ARG,
     BUFFERS_WHEN_SORTING, 4L, 100L, 0L, 1L, 0},
-  { "decode_bits", OPT_DECODE_BITS, "", (uchar**) &decode_bits,
-    (uchar**) &decode_bits, 0, GET_UINT, REQUIRED_ARG, 9L, 4L, 17L, 0L, 1L, 0},
-  { "ft_min_word_len", OPT_FT_MIN_WORD_LEN, "", (uchar**) &ft_min_word_len,
-    (uchar**) &ft_min_word_len, 0, GET_ULONG, REQUIRED_ARG, 4, 1, HA_FT_MAXCHARLEN,
+  { "decode_bits", OPT_DECODE_BITS, "", &decode_bits,
+    &decode_bits, 0, GET_UINT, REQUIRED_ARG, 9L, 4L, 17L, 0L, 1L, 0},
+  { "ft_min_word_len", OPT_FT_MIN_WORD_LEN, "", &ft_min_word_len,
+    &ft_min_word_len, 0, GET_ULONG, REQUIRED_ARG, 4, 1, HA_FT_MAXCHARLEN,
     0, 1, 0},
-  { "ft_max_word_len", OPT_FT_MAX_WORD_LEN, "", (uchar**) &ft_max_word_len,
-    (uchar**) &ft_max_word_len, 0, GET_ULONG, REQUIRED_ARG, HA_FT_MAXCHARLEN, 10,
+  { "ft_max_word_len", OPT_FT_MAX_WORD_LEN, "", &ft_max_word_len,
+    &ft_max_word_len, 0, GET_ULONG, REQUIRED_ARG, HA_FT_MAXCHARLEN, 10,
     HA_FT_MAXCHARLEN, 0, 1, 0},
   { "ft_stopword_file", OPT_FT_STOPWORD_FILE,
     "Use stopwords from this file instead of built-in list.",
-    (uchar**) &ft_stopword_file, (uchar**) &ft_stopword_file, 0, GET_STR,
+    &ft_stopword_file, &ft_stopword_file, 0, GET_STR,
     REQUIRED_ARG, 0, 0, 0, 0, 0, 0},
   {"stats_method", OPT_STATS_METHOD,
    "Specifies how index statistics collection code should treat NULLs. "
    "Possible values of name are \"nulls_unequal\" (default behavior for 4.1/5.0), "
    "\"nulls_equal\" (emulate 4.0 behavior), and \"nulls_ignored\".",
-   (uchar**) &myisam_stats_method_str, (uchar**) &myisam_stats_method_str, 0,
+   &myisam_stats_method_str, &myisam_stats_method_str, 0,
     GET_STR, REQUIRED_ARG, 0, 0, 0, 0, 0, 0},
   { 0, 0, 0, 0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0}
 };
diff --git a/storage/myisam/myisamlog.c b/storage/myisam/myisamlog.c
index fafb5140a5e..7e0d0a442a5 100644
--- a/storage/myisam/myisamlog.c
+++ b/storage/myisam/myisamlog.c
@@ -382,18 +382,18 @@ static int examine_log(char * file_name, char **table_names)
 	       curr_file_info->show_name);
       if (my_b_read(&cache,(uchar*) head,2))
 	goto err;
+      buff= 0;
       file_info.name=0;
       file_info.show_name=0;
       file_info.record=0;
-      if (read_string(&cache,(uchar**) &file_info.name,
-		      (uint) mi_uint2korr(head)))
+      if (read_string(&cache, &buff, (uint) mi_uint2korr(head)))
 	goto err;
       {
 	uint i;
 	char *pos,*to;
 
 	/* Fix if old DOS files to new format */
-	for (pos=file_info.name; (pos=strchr(pos,'\\')) ; pos++)
+	for (pos=file_info.name=(char*)buff; (pos=strchr(pos,'\\')) ; pos++)
 	  *pos= '/';
 
 	pos=file_info.name;
@@ -692,7 +692,7 @@ static int read_string(IO_CACHE *file, register uchar* *to, register uint length
     *to= 0;
     DBUG_RETURN(1);
   }
-  *((char*) *to+length)= '\0';
+  *((uchar*) *to+length)= '\0';
   DBUG_RETURN (0);
 }				/* read_string */
 
diff --git a/storage/myisam/myisampack.c b/storage/myisam/myisampack.c
index 908c32e48d3..5fcfbae8f8f 100644
--- a/storage/myisam/myisampack.c
+++ b/storage/myisam/myisampack.c
@@ -257,10 +257,10 @@ static struct my_option my_long_options[] =
    0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
 #endif
   {"backup", 'b', "Make a backup of the table as table_name.OLD.",
-   (uchar**) &backup, (uchar**) &backup, 0, GET_BOOL, NO_ARG, 0, 0, 0, 0, 0, 0},
+   &backup, &backup, 0, GET_BOOL, NO_ARG, 0, 0, 0, 0, 0, 0},
   {"character-sets-dir", OPT_CHARSETS_DIR_MP,
-   "Directory where character sets are.", (uchar**) &charsets_dir,
-   (uchar**) &charsets_dir, 0, GET_STR, REQUIRED_ARG, 0, 0, 0, 0, 0, 0},
+   "Directory where character sets are.", &charsets_dir,
+   &charsets_dir, 0, GET_STR, REQUIRED_ARG, 0, 0, 0, 0, 0, 0},
   {"debug", '#', "Output debug log. Often this is 'd:t:o,filename'.",
    0, 0, 0, GET_STR, OPT_ARG, 0, 0, 0, 0, 0, 0},
   {"force", 'f',
@@ -268,7 +268,7 @@ static struct my_option my_long_options[] =
    0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
   {"join", 'j',
    "Join all given tables into 'new_table_name'. All tables MUST have identical layouts.",
-   (uchar**) &join_table, (uchar**) &join_table, 0, GET_STR, REQUIRED_ARG, 0, 0, 0,
+   &join_table, &join_table, 0, GET_STR, REQUIRED_ARG, 0, 0, 0,
    0, 0, 0},
   {"help", '?', "Display this help and exit.",
    0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
@@ -282,8 +282,8 @@ static struct my_option my_long_options[] =
    0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
   {"version", 'V', "Output version information and exit.",
    0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
-  {"wait", 'w', "Wait and retry if table is in use.", (uchar**) &opt_wait,
-   (uchar**) &opt_wait, 0, GET_BOOL, NO_ARG, 0, 0, 0, 0, 0, 0},
+  {"wait", 'w', "Wait and retry if table is in use.", &opt_wait,
+   &opt_wait, 0, GET_BOOL, NO_ARG, 0, 0, 0, 0, 0, 0},
   { 0, 0, 0, 0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0}
 };