Fix warnings and bug spotted by gcc-4.3.

Related to operator precedence and associativity.
Make the expressions as explicit as possible.

sql/field.h:
  Silence gcc-4.3 warning: be more explicit.
sql/item.cc:
  Silence gcc-4.3 warning: be more explicit.
sql/item_sum.cc:
  Silence gcc-4.3 warning: be more explicit.
sql/log_event.cc:
  Silence gcc-4.3 warning: be more explicit.
sql/spatial.h:
  Silence gcc-4.3 warning: be more explicit.
sql/sql_lex.cc:
  Silence gcc-4.3 warning: be more explicit.
sql/table.h:
  Silence gcc-4.3 warning: be more explicit.
storage/federated/ha_federated.cc:
  Fix operator precedence bug.
storage/heap/ha_heap.cc:
  Silence gcc-4.3 warning: be more explicit.

sql/field.h

@@ -209,7 +209,7 @@ public:
     memcpy(ptr, ptr + l_offset, pack_length());
     if (null_ptr)
       *null_ptr= ((*null_ptr & (uchar) ~null_bit) |
-		  null_ptr[l_offset] & null_bit);
+		  (null_ptr[l_offset] & null_bit));
   }
   virtual bool binary() const { return 1; }
   virtual bool zero_pack() const { return 1; }

sql/item.cc

@@ -2628,7 +2628,7 @@ void Item_param::set_time(MYSQL_TIME *tm, timestamp_type time_type,
 
   if (value.time.year > 9999 || value.time.month > 12 ||
       value.time.day > 31 ||
-      time_type != MYSQL_TIMESTAMP_TIME && value.time.hour > 23 ||
+      (time_type != MYSQL_TIMESTAMP_TIME && value.time.hour > 23) ||
       value.time.minute > 59 || value.time.second > 59)
   {
     char buff[MAX_DATE_STRING_REP_LENGTH];
@@ -4840,8 +4840,8 @@ int Item::save_in_field(Field *field, bool no_conversions)
 {
   int error;
   if (result_type() == STRING_RESULT ||
-      result_type() == REAL_RESULT &&
-      field->result_type() == STRING_RESULT)
+      (result_type() == REAL_RESULT &&
+       field->result_type() == STRING_RESULT))
   {
     String *result;
     CHARSET_INFO *cs= collation.collation;

sql/item_sum.cc

@@ -654,8 +654,7 @@ Item_sum_hybrid::fix_fields(THD *thd, Item **ref)
     return TRUE;
 
   // 'item' can be changed during fix_fields
-  if (!item->fixed &&
-      item->fix_fields(thd, args) ||
+  if ((!item->fixed && item->fix_fields(thd, args)) ||
       (item= args[0])->check_cols(1))
     return TRUE;
   decimals=item->decimals;
@@ -981,8 +980,8 @@ void Item_sum_distinct::fix_length_and_dec()
     integers each <= 2^32.
   */
   if (table_field_type == MYSQL_TYPE_INT24 ||
-      table_field_type >= MYSQL_TYPE_TINY &&
-      table_field_type <= MYSQL_TYPE_LONG)
+      (table_field_type >= MYSQL_TYPE_TINY &&
+       table_field_type <= MYSQL_TYPE_LONG))
   {
     val.traits= Hybrid_type_traits_fast_decimal::instance();
     break;

sql/log_event.cc

@@ -2680,7 +2680,7 @@ void Query_log_event::print_query_header(IO_CACHE* file,
 
   if (!(flags & LOG_EVENT_SUPPRESS_USE_F) && db)
   {
-    if (different_db= memcmp(print_event_info->db, db, db_len + 1))
+    if ((different_db= memcmp(print_event_info->db, db, db_len + 1)))
       memcpy(print_event_info->db, db, db_len + 1);
     if (db[0] && different_db) 
       my_b_printf(file, "use %s%s\n", db, print_event_info->delimiter);

sql/spatial.h

@@ -117,11 +117,11 @@ struct MBR
   {
     /* The following should be safe, even if we compare doubles */
     return ((((mbr->xmin == xmax) || (mbr->xmax == xmin)) &&
-	     ((mbr->ymin >= ymin) && (mbr->ymin <= ymax) || 
-	      (mbr->ymax >= ymin) && (mbr->ymax <= ymax))) ||
+	     (((mbr->ymin >= ymin) && (mbr->ymin <= ymax)) ||
+	      ((mbr->ymax >= ymin) && (mbr->ymax <= ymax)))) ||
 	    (((mbr->ymin == ymax) || (mbr->ymax == ymin)) &&
-	     ((mbr->xmin >= xmin) && (mbr->xmin <= xmax) ||
-	      (mbr->xmax >= xmin) && (mbr->xmax <= xmax))));
+	     (((mbr->xmin >= xmin) && (mbr->xmin <= xmax)) ||
+	      ((mbr->xmax >= xmin) && (mbr->xmax <= xmax)))));
   }
 
   int within(const MBR *mbr)

sql/sql_lex.cc

@@ -2002,7 +2002,7 @@ void st_select_lex::print_limit(THD *thd,
        item->substype() == Item_subselect::ALL_SUBS))
   {
     DBUG_ASSERT(!item->fixed ||
-                select_limit->val_int() == LL(1) && offset_limit == 0);
+                (select_limit->val_int() == LL(1) && offset_limit == 0));
     return;
   }
 

sql/table.h

@@ -1363,7 +1363,7 @@ struct TABLE_LIST
   void cleanup_items();
   bool placeholder()
   {
-    return derived || view || schema_table || create && !table->db_stat ||
+    return derived || view || schema_table || (create && !table->db_stat) ||
            !table;
   }
   void print(THD *thd, String *str, enum_query_type query_type);

storage/federated/ha_federated.cc

@@ -2828,7 +2828,7 @@ int ha_federated::info(uint flag)
     if (!(row= mysql_fetch_row(result)))
       goto error;
 
-    if (flag & HA_STATUS_VARIABLE | HA_STATUS_CONST)
+    if (flag & (HA_STATUS_VARIABLE | HA_STATUS_CONST))
     {
       /*
         deleted is set in ha_federated::info

storage/heap/ha_heap.cc

@@ -91,7 +91,7 @@ const char **ha_heap::bas_ext() const
 int ha_heap::open(const char *name, int mode, uint test_if_locked)
 {
   if ((test_if_locked & HA_OPEN_INTERNAL_TABLE) ||
-      !(file= heap_open(name, mode)) && my_errno == ENOENT)
+      (!(file= heap_open(name, mode)) && my_errno == ENOENT))
   {
     HA_CREATE_INFO create_info;
     internal_table= test(test_if_locked & HA_OPEN_INTERNAL_TABLE);