Fixed BUG#6127: Stored procedure handlers within handlers don't work

    Replaced the dumb in-handler/not-in-handler check with a proper recursion
    check of handlers being executed.
    (Re-commit in a different tree, to make push possible.)


mysql-test/r/sp.result:
  New test case for BUG#6127.
mysql-test/t/sp.test:
  New test case for BUG#6127.
sql/sp_head.cc:
  Replaced the setting of ctx->in_handler with a enter/exit handler methods.
sql/sp_rcontext.cc:
  Replaced the boolean in_handler flag with a stack of handlers being exectuted, for proper recursion check.
sql/sp_rcontext.h:
  Replaced the boolean in_handler flag with a stack of handlers being exectuted, for proper recursion check.
  (And added some comments in the sp_rcontext class.)

1 files changed, 20 insertions, 7 deletions

diff --git a/sql/sp_rcontext.h b/sql/sp_rcontext.h
index 9c0fa88fe34..22fa4f6e865 100644
--- a/sql/sp_rcontext.h
+++ b/sql/sp_rcontext.h
@@ -58,7 +58,6 @@ class sp_rcontext : public Sql_alloc
 
  public:
 
-  bool in_handler;
   /*
     Arena used to (re) allocate items on . E.g. reallocate INOUT/OUT
     SP parameters when they don't fit into prealloced items. This
@@ -169,6 +168,18 @@ class sp_rcontext : public Sql_alloc
     return m_hstack[--m_hsp];
   }
 
+  inline void
+  enter_handler(int hid)
+  {
+    m_in_handler[m_ihsp++]= hid;
+  }
+
+  inline void
+  exit_handler()
+  {
+    m_ihsp-= 1;
+  }
+
   // Save variables starting at fp and up
   void
   save_variables(uint fp);
@@ -203,12 +214,14 @@ private:
 
   Item *m_result;		// For FUNCTIONs
 
-  sp_handler_t *m_handler;
-  uint m_hcount;
-  uint *m_hstack;
-  uint m_hsp;
-  int m_hfound;			// Set by find_handler; -1 if not found
-  List<Item> m_saved;		// Saved variables
+  sp_handler_t *m_handler;      // Visible handlers
+  uint m_hcount;                // Stack pointer for m_handler
+  uint *m_hstack;               // Return stack for continue handlers
+  uint m_hsp;                   // Stack pointer for m_hstack
+  uint *m_in_handler;           // Active handler, for recursion check
+  uint m_ihsp;                  // Stack pointer for m_in_handler
+  int m_hfound;                 // Set by find_handler; -1 if not found
+  List<Item> m_saved;           // Saved variables during handler exec.
 
   sp_cursor **m_cstack;
   uint m_ccount;