Merge sin.intern.azundris.com:/home/tnurnberg/27198/40-27198

into  sin.intern.azundris.com:/home/tnurnberg/27198/41-27198


sql/mysql_priv.h:
  Bug #27198: Error returns from time() are ignored
  
  manual merge
sql/sql_class.h:
  Bug #27198: Error returns from time() are ignored
  
  manual merge

sql/mysql_priv.h

@@ -408,6 +408,16 @@ int insert_precheck(THD *thd, TABLE_LIST *tables);
 int create_table_precheck(THD *thd, TABLE_LIST *tables,
 			  TABLE_LIST *create_table);
 Item *negate_expression(THD *thd, Item *expr);
+
+/* log.cc */
+void sql_perror(const char *message);
+
+void vprint_msg_to_log(enum loglevel level, const char *format, va_list args);
+void sql_print_error(const char *format, ...) ATTRIBUTE_FORMAT(printf, 1, 2);
+void sql_print_warning(const char *format, ...) ATTRIBUTE_FORMAT(printf, 1, 2);
+void sql_print_information(const char *format, ...)
+  ATTRIBUTE_FORMAT(printf, 1, 2);
+
 #include "sql_class.h"
 #include "sql_acl.h"
 #include "tztime.h"
@@ -842,14 +852,6 @@ bool check_if_key_used(TABLE *table, uint idx, List<Item> &fields);
 int key_cmp(KEY_PART_INFO *key_part, const byte *key, uint key_length);
 
 bool init_errmessage(void);
-void sql_perror(const char *message);
-
-void vprint_msg_to_log(enum loglevel level, const char *format, va_list args);
-void sql_print_error(const char *format, ...) ATTRIBUTE_FORMAT(printf, 1, 2);
-void sql_print_warning(const char *format, ...) ATTRIBUTE_FORMAT(printf, 1, 2);
-void sql_print_information(const char *format, ...)
-  ATTRIBUTE_FORMAT(printf, 1, 2);
-
 
 bool fn_format_relative_to_data_home(my_string to, const char *name,
 				     const char *dir, const char *extension);

sql/sql_class.h

@@ -1018,11 +1018,27 @@ class THD :public ilink,
     proc_info = old_msg;
     pthread_mutex_unlock(&mysys_var->mutex);
   }
+
+  static inline void safe_time(time_t *t)
+  {
+    /**
+       Wrapper around time() which retries on error (-1)
+
+       @details
+       This is needed because, despite the documentation, time() may fail
+       in some circumstances.  Here we retry time() until it succeeds, and
+       log the failure so that performance problems related to this can be
+       identified.
+    */
+    while(unlikely(time(t) == ((time_t) -1)))
+      sql_print_information("time() failed with %d", errno);
+  }
+
   inline time_t query_start() { query_start_used=1; return start_time; }
-  inline void	set_time()    { if (user_time) start_time=time_after_lock=user_time; else time_after_lock=time(&start_time); }
-  inline void	end_time()    { time(&start_time); }
+  inline void	set_time()    { if (user_time) start_time=time_after_lock=user_time; else { safe_time(&start_time); time_after_lock= start_time; }}
+  inline void	end_time()    { safe_time(&start_time); }
   inline void	set_time(time_t t) { time_after_lock=start_time=user_time=t; }
-  inline void	lock_time()   { time(&time_after_lock); }
+  inline void	lock_time()   { safe_time(&time_after_lock); }
   inline void	insert_id(ulonglong id_arg)
   {
     last_insert_id= id_arg;