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.

8 files changed, 61 insertions, 19 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);
diff --git a/mysql-test/r/partition_error.result b/mysql-test/r/partition_error.result
index 16428fba4d9..ea74f476ceb 100644
--- a/mysql-test/r/partition_error.result
+++ b/mysql-test/r/partition_error.result
@@ -1008,4 +1008,14 @@ PARTITION p VALUES LESS THAN (1219089600),
 PARTITION pmax VALUES LESS THAN MAXVALUE);
 ERROR HY000: Constant, random or timezone-dependent expressions in (sub)partitioning function are not allowed
 DROP TABLE old;
+#
+# Bug #56709: Memory leaks at running the 5.1 test suite
+# 
+CREATE TABLE t1 (a TIMESTAMP NOT NULL PRIMARY KEY);
+ALTER TABLE t1
+PARTITION BY RANGE (EXTRACT(DAY FROM a)) (
+PARTITION p VALUES LESS THAN (18),
+PARTITION pmax VALUES LESS THAN MAXVALUE);
+ERROR HY000: Constant, random or timezone-dependent expressions in (sub)partitioning function are not allowed
+DROP TABLE t1;
 End of 5.1 tests
diff --git a/mysql-test/r/variables_debug.result b/mysql-test/r/variables_debug.result
index d578fa957fc..41d77007b26 100644
--- a/mysql-test/r/variables_debug.result
+++ b/mysql-test/r/variables_debug.result
@@ -24,4 +24,17 @@ SELECT @@global.debug;
 @@global.debug
 
 SET GLOBAL debug=@old_debug;
+#
+# Bug #56709: Memory leaks at running the 5.1 test suite
+# 
+SET @old_local_debug = @@debug;
+SET @@debug='d,foo';
+SELECT @@debug;
+@@debug
+d,foo
+SET @@debug='';
+SELECT @@debug;
+@@debug
+
+SET @@debug = @old_local_debug;
 End of 5.1 tests
diff --git a/mysql-test/t/partition_error.test b/mysql-test/t/partition_error.test
index 434392c2e28..d3f10628254 100644
--- a/mysql-test/t/partition_error.test
+++ b/mysql-test/t/partition_error.test
@@ -1252,4 +1252,18 @@ PARTITION pmax VALUES LESS THAN MAXVALUE);
 
 DROP TABLE old;
 
+--echo #
+--echo # Bug #56709: Memory leaks at running the 5.1 test suite
+--echo # 
+
+CREATE TABLE t1 (a TIMESTAMP NOT NULL PRIMARY KEY);
+
+--error ER_WRONG_EXPR_IN_PARTITION_FUNC_ERROR
+ALTER TABLE t1
+PARTITION BY RANGE (EXTRACT(DAY FROM a)) (
+PARTITION p VALUES LESS THAN (18),
+PARTITION pmax VALUES LESS THAN MAXVALUE);
+
+DROP TABLE t1;
+
 --echo End of 5.1 tests
diff --git a/mysql-test/t/variables_debug.test b/mysql-test/t/variables_debug.test
index 12f5d2e6ca5..e6f1bbddc2a 100644
--- a/mysql-test/t/variables_debug.test
+++ b/mysql-test/t/variables_debug.test
@@ -25,4 +25,17 @@ SELECT @@global.debug;
 
 SET GLOBAL debug=@old_debug;
 
+--echo #
+--echo # Bug #56709: Memory leaks at running the 5.1 test suite
+--echo # 
+
+SET @old_local_debug = @@debug;
+
+SET @@debug='d,foo';
+SELECT @@debug;
+SET @@debug='';
+SELECT @@debug;
+
+SET @@debug = @old_local_debug;
+
 --echo End of 5.1 tests
diff --git a/sql/item_timefunc.cc b/sql/item_timefunc.cc
index dff4d20f347..103bd96efd4 100644
--- a/sql/item_timefunc.cc
+++ b/sql/item_timefunc.cc
@@ -2270,8 +2270,6 @@ void Item_extract::print(String *str, enum_query_type query_type)
 
 void Item_extract::fix_length_and_dec()
 {
-  value.alloc(32);				// alloc buffer
-
   maybe_null=1;					// If wrong date
   switch (int_type) {
   case INTERVAL_YEAR:		max_length=4; date_value=1; break;
@@ -2314,6 +2312,8 @@ longlong Item_extract::val_int()
   }
   else
   {
+    char buf[40];
+    String value(buf, sizeof(buf), &my_charset_bin);;
     String *res= args[0]->val_str(&value);
     if (!res || str_to_time_with_warn(res->ptr(), res->length(), &ltime))
     {
diff --git a/sql/item_timefunc.h b/sql/item_timefunc.h
index 11eed70f399..ef86406e1be 100644
--- a/sql/item_timefunc.h
+++ b/sql/item_timefunc.h
@@ -702,7 +702,6 @@ public:
 
 class Item_extract :public Item_int_func
 {
-  String value;
   bool date_value;
  public:
   const interval_type int_type; // keep it public
diff --git a/sql/sql_load.cc b/sql/sql_load.cc
index f9386206dce..4b68f2a3821 100644
--- a/sql/sql_load.cc
+++ b/sql/sql_load.cc
@@ -1116,6 +1116,7 @@ READ_INFO::READ_INFO(File file_par, uint tot_length, CHARSET_INFO *cs,
 		      MYF(MY_WME)))
     {
       my_free((uchar*) buffer,MYF(0)); /* purecov: inspected */
+      buffer= NULL;
       error=1;
     }
     else
@@ -1142,13 +1143,10 @@ READ_INFO::READ_INFO(File file_par, uint tot_length, CHARSET_INFO *cs,
 
 READ_INFO::~READ_INFO()
 {
-  if (!error)
-  {
-    if (need_end_io_cache)
-      ::end_io_cache(&cache);
-    my_free((uchar*) buffer,MYF(0));
-    error=1;
-  }
+  if (!error && need_end_io_cache)
+    ::end_io_cache(&cache);
+
+  my_free(buffer, MYF(MY_ALLOW_ZERO_PTR));
 }