Bug #56709: Memory leaks at running the 5.1 test suite

Fixed a number of memory leaks discovered by valgrind.

dbug/dbug.c:
  This is actually an addendum to the fix for bug #52629:
  
  - there is no point in limiting the fix to just global
  variables, session ones are also affected.
  - zero all fields when allocating a new 'state' structure so
  that FreeState() does not deal with unitialized data later.
  - add a check for a NULL pointer in DBUGCloseFile()
mysql-test/r/partition_error.result:
  Added a test case for bug #56709.
mysql-test/r/variables_debug.result:
  Added a test case for bug #56709.
mysql-test/t/partition_error.test:
  Added a test case for bug #56709.
mysql-test/t/variables_debug.test:
  Added a test case for bug #56709.
sql/item_timefunc.cc:
  There is no point in declaring 'value' as a member of
  Item_extract and dynamically allocating memory for it in
  Item_extract::fix_length_and_dec(), since this string is only
  used as a temporary storage in Item_extract::val_int().
sql/item_timefunc.h:
  Removed 'value' from the Item_extract class definition.
sql/sql_load.cc:
  - we may need to deallocate 'buffer' even when 'error' is
    non-zero in some cases, since 'error' is public, and there is
    external code modifying it.
  - assign NULL to buffer when deallocating it so that we don't
    do it twice in the destructor
  - there is no point in changing 'error' in the destructor.

1 files changed, 4 insertions, 9 deletions

diff --git a/dbug/dbug.c b/dbug/dbug.c
index 8fa5ed9af6b..76723fa8767 100644
--- a/dbug/dbug.c
+++ b/dbug/dbug.c
@@ -455,13 +455,8 @@ static void DbugParse(CODE_STATE *cs, const char *control)
   rel= control[0] == '+' || control[0] == '-';
   if ((!rel || (!stack->out_file && !stack->next)))
   {
-    /*
-      We need to free what's already in init_settings, because unlike
-      the thread related stack frames there's a chance that something
-      is in these variables already.
-    */
-    if (stack == &init_settings)
-      FreeState(cs, stack, 0);
+    /* Free memory associated with the state before resetting its members */
+    FreeState(cs, stack, 0);
     stack->flags= 0;
     stack->delay= 0;
     stack->maxdepth= 0;
@@ -1447,8 +1442,8 @@ static void PushState(CODE_STATE *cs)
   struct settings *new_malloc;
 
   new_malloc= (struct settings *) DbugMalloc(sizeof(struct settings));
+  bzero(new_malloc, sizeof(struct settings));
   new_malloc->next= cs->stack;
-  new_malloc->out_file= NULL;
   cs->stack= new_malloc;
 }
 
@@ -1957,7 +1952,7 @@ static FILE *OpenProfile(CODE_STATE *cs, const char *name)
 
 static void DBUGCloseFile(CODE_STATE *cs, FILE *fp)
 {
-  if (fp != stderr && fp != stdout && fclose(fp) == EOF)
+  if (fp != NULL && fp != stderr && fp != stdout && fclose(fp) == EOF)
   {
     pthread_mutex_lock(&THR_LOCK_dbug);
     (void) fprintf(cs->stack->out_file, ERR_CLOSE, cs->process);