Bug#36443 Server crashes when executing insert when insert trigger on table

                        
      The crash appeared to be a result of allocating an instance of Discrete_interval 
      automatically that that was referred in out-of-declaration scope.
                        
      Fixed with correcting backing up and restoring scheme of
      auto_inc_intervals_forced, introduced by bug#33029, by means of shallow copying;
      added simulation code that forces executing those fixes of the former bug that
      targeted at master-and-slave having incompatible bug#33029-prone versions.

mysql-test/suite/bugs/r/rpl_bug33029.result:
  new results file
mysql-test/suite/bugs/t/rpl_bug33029.test:
  test merely checks no crash happens on slave.
sql/slave.cc:
  forcing to execute special logics implemented for bug#33029 if
  simulate_bug33029 the debug option is set.
sql/sql_class.cc:
  swaps of backed and the actual auto_inc_intervals_forced basing on shallow coping.
sql/structs.h:
  Removing the deep _copy() and methods associated with it;
  adding methods to Discrete_intervals_list:
      
  private `=', copy constructor to prevent using;
  private set_members();
  public  copy_shallow(), swap(), get_{head, tail, current}();
          empty_no_free() through set_members().

1 files changed, 32 insertions, 21 deletions

diff --git a/sql/structs.h b/sql/structs.h
index 809175fdde4..0a20eee0e9a 100644
--- a/sql/structs.h
+++ b/sql/structs.h
@@ -314,31 +314,22 @@ private:
   */
   Discrete_interval        *current;
   uint                  elements; // number of elements
-
-  /* helper function for copy construct and assignment operator */
-  void copy_(const Discrete_intervals_list& from)
-  {
-    for (Discrete_interval *i= from.head; i; i= i->next)
-    {
-      Discrete_interval j= *i;
-      append(&j);
-    }
+  void set_members(Discrete_interval *h, Discrete_interval *t,
+                   Discrete_interval *c, uint el)
+  {  
+    head= h;
+    tail= t;
+    current= c;
+    elements= el;
   }
+  void operator=(Discrete_intervals_list &);  /* prevent use of these */
+  Discrete_intervals_list(const Discrete_intervals_list &);
+
 public:
   Discrete_intervals_list() : head(NULL), current(NULL), elements(0) {};
-  Discrete_intervals_list(const Discrete_intervals_list& from)
-  {
-    copy_(from);
-  }
-  void operator=(const Discrete_intervals_list& from)
-  {
-    empty();
-    copy_(from);
-  }
   void empty_no_free()
   {
-    head= current= NULL;
-    elements= 0;
+    set_members(NULL, NULL, NULL, 0);
   }
   void empty()
   {
@@ -350,7 +341,24 @@ public:
     }
     empty_no_free();
   }
-
+  void copy_shallow(const Discrete_intervals_list * dli)
+  {
+    head= dli->get_head();
+    tail= dli->get_tail();
+    current= dli->get_current();
+    elements= dli->nb_elements();
+  }
+  void swap (Discrete_intervals_list * dli)
+  {
+    Discrete_interval *h, *t, *c;
+    uint el;
+    h= dli->get_head();
+    t= dli->get_tail();
+    c= dli->get_current();
+    el= dli->nb_elements();
+    dli->copy_shallow(this);
+    set_members(h, t, c, el);
+  }
   const Discrete_interval* get_next()
   {
     Discrete_interval *tmp= current;
@@ -364,4 +372,7 @@ public:
   ulonglong minimum()     const { return (head ? head->minimum() : 0); };
   ulonglong maximum()     const { return (head ? tail->maximum() : 0); };
   uint      nb_elements() const { return elements; }
+  Discrete_interval* get_head() const { return head; };
+  Discrete_interval* get_tail() const { return tail; };
+  Discrete_interval* get_current() const { return current; };
 };