MDEV-10587 sql_mode=ORACLE: User defined exceptions

12 files changed, 655 insertions, 113 deletions

diff --git a/mysql-test/suite/compat/oracle/r/exception.result b/mysql-test/suite/compat/oracle/r/exception.result
index 7366f147f2a..9c40252a163 100644
--- a/mysql-test/suite/compat/oracle/r/exception.result
+++ b/mysql-test/suite/compat/oracle/r/exception.result
@@ -220,3 +220,164 @@ DROP TABLE t1;
 #
 # End of MDEV-10840 sql_mode=ORACLE: RAISE statement for predefined exceptions
 #
+#
+# MDEV-10587 sql_mode=ORACLE: User defined exceptions
+#
+#
+# Checking that duplicate WHEN clause is not allowed
+#
+CREATE FUNCTION f1() RETURN VARCHAR
+AS
+e EXCEPTION;
+BEGIN
+RETURN 'Got no exceptions';
+EXCEPTION
+WHEN e THEN RETURN 'Got exception e';
+WHEN e THEN RETURN 'Got exception e';
+END;
+$$
+ERROR 42000: Duplicate handler declared in the same block
+#
+# Checking that raised user exceptions are further caught by name
+#
+CREATE FUNCTION f1(c VARCHAR) RETURN VARCHAR
+AS
+e EXCEPTION;
+f EXCEPTION;
+BEGIN
+IF c = 'e' THEN RAISE e; END IF;
+IF c = 'f' THEN RAISE f; END IF;
+RETURN 'Got no exceptions';
+EXCEPTION
+WHEN e THEN RETURN 'Got exception e';
+END;
+$$
+SELECT f1('');
+f1('')
+Got no exceptions
+SELECT f1('e');
+f1('e')
+Got exception e
+SELECT f1('f');
+ERROR 45000: Unhandled user-defined exception condition
+DROP FUNCTION f1;
+#
+# Checking that raised user exceptions are further caught by OTHERS
+#
+CREATE FUNCTION f1(c VARCHAR) RETURN VARCHAR
+AS
+e EXCEPTION;
+f EXCEPTION;
+BEGIN
+IF c = 'e' THEN RAISE e; END IF;
+IF c = 'f' THEN RAISE f; END IF;
+RETURN 'Got no exceptions';
+EXCEPTION
+WHEN OTHERS THEN RETURN 'Got some exception';
+END;
+$$
+SELECT f1('');
+f1('')
+Got no exceptions
+SELECT f1('e');
+f1('e')
+Got some exception
+SELECT f1('f');
+f1('f')
+Got some exception
+DROP FUNCTION f1;
+#
+# Checking that 'WHEN e .. WHEN f' does not produce ER_SP_DUP_HANDLER
+#
+CREATE FUNCTION f1(c VARCHAR) RETURN VARCHAR
+AS
+e EXCEPTION;
+f EXCEPTION;
+a VARCHAR(64):='';
+BEGIN
+BEGIN
+IF c = 'e' THEN RAISE e; END IF;
+IF c = 'f' THEN RAISE f; END IF;
+EXCEPTION
+WHEN e THEN BEGIN a:='Got EXCEPTION1/e; '; RAISE e; END;
+WHEN f THEN BEGIN a:='Got EXCEPTION1/f; '; RAISE f; END;
+END;
+RETURN 'Got no exceptions';
+EXCEPTION
+WHEN OTHERS THEN RETURN a || 'Got EXCEPTION2/OTHERS;';
+END;
+$$
+SELECT f1('');
+f1('')
+Got no exceptions
+SELECT f1('e');
+f1('e')
+Got EXCEPTION1/e; Got EXCEPTION2/OTHERS;
+SELECT f1('f');
+f1('f')
+Got EXCEPTION1/f; Got EXCEPTION2/OTHERS;
+DROP FUNCTION f1;
+#
+# Checking that resignaled user exceptions are further caught by name
+#
+CREATE FUNCTION f1(c VARCHAR) RETURN VARCHAR
+AS
+e EXCEPTION;
+f EXCEPTION;
+a VARCHAR(64):='';
+BEGIN
+BEGIN
+IF c = 'e' THEN RAISE e; END IF;
+IF c = 'f' THEN RAISE f; END IF;
+EXCEPTION
+WHEN e THEN BEGIN a:='Got EXCEPTION1/e; '; RAISE; END;
+WHEN f THEN BEGIN a:='Got EXCEPTION1/f; '; RAISE; END;
+END;
+RETURN 'Got no exceptions';
+EXCEPTION
+WHEN e THEN RETURN a || 'Got EXCEPTION2/e;';
+END;
+$$
+SELECT f1('');
+f1('')
+Got no exceptions
+SELECT f1('e');
+f1('e')
+Got EXCEPTION1/e; Got EXCEPTION2/e;
+SELECT f1('f');
+ERROR 45000: Unhandled user-defined exception condition
+DROP FUNCTION f1;
+#
+# Checking that resignaled user exceptions are further caught by OTHERS
+#
+CREATE FUNCTION f1(c VARCHAR) RETURN VARCHAR
+AS
+e EXCEPTION;
+f EXCEPTION;
+a VARCHAR(64):='';
+BEGIN
+BEGIN
+IF c = 'e' THEN RAISE e; END IF;
+IF c = 'f' THEN RAISE f; END IF;
+EXCEPTION
+WHEN e THEN BEGIN a:='Got EXCEPTION1/e; '; RAISE; END;
+WHEN f THEN BEGIN a:='Got EXCEPTION1/f; '; RAISE; END;
+END;
+RETURN 'Got no exceptions';
+EXCEPTION
+WHEN OTHERS THEN RETURN a || 'Got EXCEPTION2/OTHERS;';
+END;
+$$
+SELECT f1('');
+f1('')
+Got no exceptions
+SELECT f1('e');
+f1('e')
+Got EXCEPTION1/e; Got EXCEPTION2/OTHERS;
+SELECT f1('f');
+f1('f')
+Got EXCEPTION1/f; Got EXCEPTION2/OTHERS;
+DROP FUNCTION f1;
+#
+# End of MDEV-10587 sql_mode=ORACLE: User defined exceptions
+#
diff --git a/mysql-test/suite/compat/oracle/t/exception.test b/mysql-test/suite/compat/oracle/t/exception.test
index 2bb27433a4d..07061abb6bc 100644
--- a/mysql-test/suite/compat/oracle/t/exception.test
+++ b/mysql-test/suite/compat/oracle/t/exception.test
@@ -264,3 +264,170 @@ DROP TABLE t1;
 --echo #
 --echo # End of MDEV-10840 sql_mode=ORACLE: RAISE statement for predefined exceptions
 --echo #
+
+
+--echo #
+--echo # MDEV-10587 sql_mode=ORACLE: User defined exceptions
+--echo #
+
+--echo #
+--echo # Checking that duplicate WHEN clause is not allowed
+--echo #
+
+DELIMITER $$;
+--error ER_SP_DUP_HANDLER
+CREATE FUNCTION f1() RETURN VARCHAR
+AS
+  e EXCEPTION;
+BEGIN
+  RETURN 'Got no exceptions';
+EXCEPTION
+  WHEN e THEN RETURN 'Got exception e';
+  WHEN e THEN RETURN 'Got exception e';
+END;
+$$
+DELIMITER ;$$
+
+
+--echo #
+--echo # Checking that raised user exceptions are further caught by name
+--echo #
+
+DELIMITER $$;
+CREATE FUNCTION f1(c VARCHAR) RETURN VARCHAR
+AS
+  e EXCEPTION;
+  f EXCEPTION;
+BEGIN
+  IF c = 'e' THEN RAISE e; END IF;
+  IF c = 'f' THEN RAISE f; END IF;
+  RETURN 'Got no exceptions';
+EXCEPTION
+  WHEN e THEN RETURN 'Got exception e';
+END;
+$$
+DELIMITER ;$$
+SELECT f1('');
+SELECT f1('e');
+--error ER_SIGNAL_EXCEPTION
+SELECT f1('f');
+DROP FUNCTION f1;
+
+
+--echo #
+--echo # Checking that raised user exceptions are further caught by OTHERS
+--echo #
+
+DELIMITER $$;
+CREATE FUNCTION f1(c VARCHAR) RETURN VARCHAR
+AS
+  e EXCEPTION;
+  f EXCEPTION;
+BEGIN
+  IF c = 'e' THEN RAISE e; END IF;
+  IF c = 'f' THEN RAISE f; END IF;
+  RETURN 'Got no exceptions';
+EXCEPTION
+  WHEN OTHERS THEN RETURN 'Got some exception';
+END;
+$$
+DELIMITER ;$$
+SELECT f1('');
+SELECT f1('e');
+SELECT f1('f');
+DROP FUNCTION f1;
+
+
+--echo #
+--echo # Checking that 'WHEN e .. WHEN f' does not produce ER_SP_DUP_HANDLER
+--echo #
+
+DELIMITER $$;
+CREATE FUNCTION f1(c VARCHAR) RETURN VARCHAR
+AS
+  e EXCEPTION;
+  f EXCEPTION;
+  a VARCHAR(64):='';
+BEGIN
+  BEGIN
+    IF c = 'e' THEN RAISE e; END IF;
+    IF c = 'f' THEN RAISE f; END IF;
+  EXCEPTION
+    WHEN e THEN BEGIN a:='Got EXCEPTION1/e; '; RAISE e; END;
+    WHEN f THEN BEGIN a:='Got EXCEPTION1/f; '; RAISE f; END;
+  END;
+  RETURN 'Got no exceptions';
+EXCEPTION
+  WHEN OTHERS THEN RETURN a || 'Got EXCEPTION2/OTHERS;';
+END;
+$$
+DELIMITER ;$$
+SELECT f1('');
+SELECT f1('e');
+SELECT f1('f');
+DROP FUNCTION f1;
+
+
+--echo #
+--echo # Checking that resignaled user exceptions are further caught by name
+--echo #
+DELIMITER $$;
+CREATE FUNCTION f1(c VARCHAR) RETURN VARCHAR
+AS
+  e EXCEPTION;
+  f EXCEPTION;
+  a VARCHAR(64):='';
+BEGIN
+  BEGIN
+    IF c = 'e' THEN RAISE e; END IF;
+    IF c = 'f' THEN RAISE f; END IF;
+  EXCEPTION
+    WHEN e THEN BEGIN a:='Got EXCEPTION1/e; '; RAISE; END;
+    WHEN f THEN BEGIN a:='Got EXCEPTION1/f; '; RAISE; END;
+  END;
+  RETURN 'Got no exceptions';
+EXCEPTION
+  WHEN e THEN RETURN a || 'Got EXCEPTION2/e;';
+END;
+$$
+DELIMITER ;$$
+SELECT f1('');
+SELECT f1('e');
+--error ER_SIGNAL_EXCEPTION
+SELECT f1('f');
+DROP FUNCTION f1;
+
+
+--echo #
+--echo # Checking that resignaled user exceptions are further caught by OTHERS
+--echo #
+
+DELIMITER $$;
+CREATE FUNCTION f1(c VARCHAR) RETURN VARCHAR
+AS
+  e EXCEPTION;
+  f EXCEPTION;
+  a VARCHAR(64):='';
+BEGIN
+  BEGIN
+    IF c = 'e' THEN RAISE e; END IF;
+    IF c = 'f' THEN RAISE f; END IF;
+  EXCEPTION
+    WHEN e THEN BEGIN a:='Got EXCEPTION1/e; '; RAISE; END;
+    WHEN f THEN BEGIN a:='Got EXCEPTION1/f; '; RAISE; END;
+  END;
+  RETURN 'Got no exceptions';
+EXCEPTION
+  WHEN OTHERS THEN RETURN a || 'Got EXCEPTION2/OTHERS;';
+END;
+$$
+DELIMITER ;$$
+SELECT f1('');
+SELECT f1('e');
+SELECT f1('f');
+DROP FUNCTION f1;
+
+
+--echo #
+--echo # End of MDEV-10587 sql_mode=ORACLE: User defined exceptions
+--echo #
diff --git a/sql/sp_pcontext.cc b/sql/sp_pcontext.cc
index 0937dfdb081..047d0f50aaa 100644
--- a/sql/sp_pcontext.cc
+++ b/sql/sp_pcontext.cc
@@ -27,10 +27,41 @@ bool sp_condition_value::equals(const sp_condition_value *cv) const
 {
   DBUG_ASSERT(cv);
 
+  /*
+    The following test disallows duplicate handlers,
+    including user defined exceptions with the same WHEN clause:
+      DECLARE
+        a EXCEPTION;
+        b EXCEPTION;
+      BEGIN
+        RAUSE a;
+      EXCEPTION
+        WHEN a THEN RETURN 'a0';
+        WHEN a THEN RETURN 'a1';
+      END
+  */
   if (this == cv)
     return true;
 
-  if (type != cv->type)
+  /*
+    The test below considers two conditions of the same type as equal
+    (except for the user defined exceptions) to avoid declaring duplicate
+    handlers.
+
+    All user defined conditions have type==SQLSTATE
+    with the same SQL state and error code.
+    It's OK to have multiple user defined conditions:
+    DECLARE
+      a EXCEPTION;
+      b EXCEPTION;
+    BEGIN
+      RAISE a;
+    EXCEPTION
+      WHEN a THEN RETURN 'a';
+      WHEN b THEN RETURN 'b';
+    END;
+  */
+  if (type != cv->type || m_is_user_defined || cv->m_is_user_defined)
     return false;
 
   switch (type)
@@ -353,9 +384,57 @@ bool sp_pcontext::check_duplicate_handler(
 }
 
 
+bool sp_condition_value::matches(const Sql_condition_identity &value,
+                                 const sp_condition_value *found_cv) const
+{
+  bool user_value_matched= !value.get_user_condition_value() ||
+                           this == value.get_user_condition_value();
+
+  switch (type)
+  {
+  case sp_condition_value::ERROR_CODE:
+    return user_value_matched &&
+           value.get_sql_errno() == get_sql_errno() &&
+           (!found_cv || found_cv->type > sp_condition_value::ERROR_CODE);
+
+  case sp_condition_value::SQLSTATE:
+    return user_value_matched &&
+           Sql_state::eq(&value) &&
+           (!found_cv || found_cv->type > sp_condition_value::SQLSTATE);
+
+  case sp_condition_value::WARNING:
+    return user_value_matched &&
+           (value.Sql_state::is_warning() ||
+            value.get_level() == Sql_condition::WARN_LEVEL_WARN) &&
+           !found_cv;
+
+  case sp_condition_value::NOT_FOUND:
+    return user_value_matched &&
+           value.Sql_state::is_not_found() &&
+           !found_cv;
+
+  case sp_condition_value::EXCEPTION:
+    /*
+      In sql_mode=ORACLE this construct should catch both errors and warnings:
+        EXCEPTION
+          WHEN OTHERS THEN ...;
+      E.g. NO_DATA_FOUND is more like a warning than an error,
+      and it should be caught.
+
+      We don't check user_value_matched here.
+      "WHEN OTHERS" catches all user defined exception.
+    */
+    return (((current_thd->variables.sql_mode & MODE_ORACLE) ||
+           (value.Sql_state::is_exception() &&
+            value.get_level() == Sql_condition::WARN_LEVEL_ERROR)) &&
+           !found_cv);
+  }
+  return false;
+}
+
+
 sp_handler*
-sp_pcontext::find_handler(const Sql_state_errno *value,
-                          Sql_condition::enum_warning_level level) const
+sp_pcontext::find_handler(const Sql_condition_identity &value) const
 {
   sp_handler *found_handler= NULL;
   sp_condition_value *found_cv= NULL;
@@ -369,61 +448,10 @@ sp_pcontext::find_handler(const Sql_state_errno *value,
 
     while ((cv= li++))
     {
-      switch (cv->type)
+      if (cv->matches(value, found_cv))
       {
-      case sp_condition_value::ERROR_CODE:
-        if (value->get_sql_errno() == cv->get_sql_errno() &&
-            (!found_cv ||
-             found_cv->type > sp_condition_value::ERROR_CODE))
-        {
-          found_cv= cv;
-          found_handler= h;
-        }
-        break;
-
-      case sp_condition_value::SQLSTATE:
-        if (cv->Sql_state::eq(value) &&
-            (!found_cv ||
-             found_cv->type > sp_condition_value::SQLSTATE))
-        {
-          found_cv= cv;
-          found_handler= h;
-        }
-        break;
-
-      case sp_condition_value::WARNING:
-        if ((value->Sql_state::is_warning() ||
-             level == Sql_condition::WARN_LEVEL_WARN) && !found_cv)
-        {
-          found_cv= cv;
-          found_handler= h;
-        }
-        break;
-
-      case sp_condition_value::NOT_FOUND:
-        if (value->Sql_state::is_not_found() && !found_cv)
-        {
-          found_cv= cv;
-          found_handler= h;
-        }
-        break;
-
-      case sp_condition_value::EXCEPTION:
-        /*
-          In sql_mode=ORACLE this construct should catch errors and warnings:
-            EXCEPTION
-              WHEN OTHERS THEN ...;
-          E.g. NO_DATA_FOUND is more like a warning than an error,
-          and it should be caught.
-        */
-        if (((current_thd->variables.sql_mode & MODE_ORACLE) ||
-             (value->Sql_state::is_exception() &&
-              level == Sql_condition::WARN_LEVEL_ERROR)) && !found_cv)
-        {
-          found_cv= cv;
-          found_handler= h;
-        }
-        break;
+        found_cv= cv;
+        found_handler= h;
       }
     }
   }
@@ -466,7 +494,7 @@ sp_pcontext::find_handler(const Sql_state_errno *value,
   if (!p || !p->m_parent)
     return NULL;
 
-  return p->m_parent->find_handler(value, level);
+  return p->m_parent->find_handler(value);
 }
 
 
diff --git a/sql/sp_pcontext.h b/sql/sp_pcontext.h
index d97643e5ade..f30596cc02b 100644
--- a/sql/sp_pcontext.h
+++ b/sql/sp_pcontext.h
@@ -129,6 +129,7 @@ public:
 
 class sp_condition_value : public Sql_alloc, public Sql_state_errno
 {
+  bool m_is_user_defined;
 public:
   enum enum_type
   {
@@ -146,23 +147,27 @@ public:
   sp_condition_value(uint _mysqlerr)
    :Sql_alloc(),
     Sql_state_errno(_mysqlerr),
+    m_is_user_defined(false),
     type(ERROR_CODE)
   { }
 
   sp_condition_value(uint _mysqlerr, const char *_sql_state)
    :Sql_alloc(),
     Sql_state_errno(_mysqlerr, _sql_state),
+    m_is_user_defined(false),
     type(ERROR_CODE)
   { }
 
-  sp_condition_value(const char *_sql_state)
+  sp_condition_value(const char *_sql_state, bool is_user_defined= false)
    :Sql_alloc(),
     Sql_state_errno(0, _sql_state),
+    m_is_user_defined(is_user_defined),
     type(SQLSTATE)
   { }
 
   sp_condition_value(enum_type _type)
    :Sql_alloc(),
+    m_is_user_defined(false),
     type(_type)
   {
     DBUG_ASSERT(type != ERROR_CODE && type != SQLSTATE);
@@ -174,8 +179,39 @@ public:
   ///
   /// @return true if the instances are equal, false otherwise.
   bool equals(const sp_condition_value *cv) const;
+
+
+  /**
+    Checks if this condition is OK for search.
+    See also sp_context::find_handler().
+
+    @param identity - The condition identity
+    @param found_cv - A previously found matching condition or NULL.
+    @return true    - If the current value matches identity and
+                      makes a stronger match than the previously
+                      found condition found_cv.
+    @return false   - If the current value does not match identity,
+                      of the current value makes a weaker match than found_cv.
+  */
+  bool matches(const Sql_condition_identity &identity,
+               const sp_condition_value *found_cv) const;
+
+  Sql_user_condition_identity get_user_condition_identity() const
+  {
+    return Sql_user_condition_identity(m_is_user_defined ? this : NULL);
+  }
 };
 
+
+class sp_condition_value_user_defined: public sp_condition_value
+{
+public:
+  sp_condition_value_user_defined()
+   :sp_condition_value("45000", true)
+  { }
+};
+
+
 ///////////////////////////////////////////////////////////////////////////
 
 /// This class represents 'DECLARE CONDITION' statement.
@@ -516,8 +552,7 @@ public:
   /// @param level            The SQL condition level
   ///
   /// @return a pointer to the found SQL-handler or NULL.
-  sp_handler *find_handler(const Sql_state_errno *value,
-                           Sql_condition::enum_warning_level level) const;
+  sp_handler *find_handler(const Sql_condition_identity &identity) const;
 
   /////////////////////////////////////////////////////////////////////////
   // Cursors.
diff --git a/sql/sp_rcontext.cc b/sql/sp_rcontext.cc
index 242e1b122d5..488fb85a69f 100644
--- a/sql/sp_rcontext.cc
+++ b/sql/sp_rcontext.cc
@@ -228,7 +228,7 @@ bool sp_rcontext::handle_sql_condition(THD *thd,
   if (thd->is_error())
   {
     found_handler=
-      cur_spi->m_ctx->find_handler(da, Sql_condition::WARN_LEVEL_ERROR);
+      cur_spi->m_ctx->find_handler(da->get_error_condition_identity());
 
     if (found_handler)
       found_condition= da->get_error_condition();
@@ -244,7 +244,8 @@ bool sp_rcontext::handle_sql_condition(THD *thd,
     {
       found_condition=
         new (callers_arena->mem_root) Sql_condition(callers_arena->mem_root,
-                                                    da, da->message());
+                                                    da->get_error_condition_identity(),
+                                                    da->message());
     }
   }
   else if (da->current_statement_warn_count())
@@ -261,8 +262,7 @@ bool sp_rcontext::handle_sql_condition(THD *thd,
       if (c->get_level() == Sql_condition::WARN_LEVEL_WARN ||
           c->get_level() == Sql_condition::WARN_LEVEL_NOTE)
       {
-        const sp_handler *handler=
-          cur_spi->m_ctx->find_handler(c, c->get_level());
+        const sp_handler *handler= cur_spi->m_ctx->find_handler(*c);
         if (handler)
         {
           found_handler= handler;
diff --git a/sql/sp_rcontext.h b/sql/sp_rcontext.h
index d2e1f5fec58..d040186ec34 100644
--- a/sql/sp_rcontext.h
+++ b/sql/sp_rcontext.h
@@ -120,7 +120,8 @@ public:
   /// standard SQL-condition processing (Diagnostics_area should contain an
   /// object for active SQL-condition, not just information stored in DA's
   /// fields).
-  class Sql_condition_info : public Sql_alloc, public Sql_state_errno_level
+  class Sql_condition_info : public Sql_alloc,
+                             public Sql_condition_identity
   {
   public:
     /// Text message.
@@ -132,7 +133,7 @@ public:
     /// @param arena           Query arena for SP
     Sql_condition_info(const Sql_condition *_sql_condition,
                        Query_arena *arena)
-      :Sql_state_errno_level(*_sql_condition)
+      :Sql_condition_identity(*_sql_condition)
     {
       message= strdup_root(arena->mem_root, _sql_condition->get_message_text());
     }
diff --git a/sql/sql_class.cc b/sql/sql_class.cc
index 5ced78ec52a..25052e84e96 100644
--- a/sql/sql_class.cc
+++ b/sql/sql_class.cc
@@ -1066,9 +1066,10 @@ void THD::raise_note_printf(uint sql_errno, ...)
 }
 
 Sql_condition* THD::raise_condition(uint sql_errno,
-                                  const char* sqlstate,
-                                  Sql_condition::enum_warning_level level,
-                                  const char* msg)
+                                    const char* sqlstate,
+                                    Sql_condition::enum_warning_level level,
+                                    const Sql_user_condition_identity &ucid,
+                                    const char* msg)
 {
   Diagnostics_area *da= get_stmt_da();
   Sql_condition *cond= NULL;
@@ -1127,7 +1128,7 @@ Sql_condition* THD::raise_condition(uint sql_errno,
     if (!da->is_error())
     {
       set_row_count_func(-1);
-      da->set_error_status(sql_errno, msg, sqlstate, cond);
+      da->set_error_status(sql_errno, msg, sqlstate, ucid, cond);
     }
   }
 
@@ -1141,7 +1142,7 @@ Sql_condition* THD::raise_condition(uint sql_errno,
   if (!(is_fatal_error && (sql_errno == EE_OUTOFMEMORY ||
                            sql_errno == ER_OUTOFMEMORY)))
   {
-    cond= da->push_warning(this, sql_errno, sqlstate, level, msg);
+    cond= da->push_warning(this, sql_errno, sqlstate, level, ucid, msg);
   }
   DBUG_RETURN(cond);
 }
diff --git a/sql/sql_class.h b/sql/sql_class.h
index 6345e8c1cdf..86cb6036be3 100644
--- a/sql/sql_class.h
+++ b/sql/sql_class.h
@@ -3939,8 +3939,42 @@ private:
   raise_condition(uint sql_errno,
                   const char* sqlstate,
                   Sql_condition::enum_warning_level level,
+                  const char* msg)
+  {
+    return raise_condition(sql_errno, sqlstate, level,
+                           Sql_user_condition_identity(), msg);
+  }
+
+  /**
+    Raise a generic or a user defined SQL condition.
+    @param ucid      - the user condition identity
+                       (or an empty identity if not a user condition)
+    @param sql_errno - the condition error number
+    @param sqlstate  - the condition SQLSTATE
+    @param level     - the condition level
+    @param msg       - the condition message text
+    @return The condition raised, or NULL
+  */
+  Sql_condition*
+  raise_condition(uint sql_errno,
+                  const char* sqlstate,
+                  Sql_condition::enum_warning_level level,
+                  const Sql_user_condition_identity &ucid,
                   const char* msg);
 
+  Sql_condition*
+  raise_condition(const Sql_condition *cond)
+  {
+    Sql_condition *raised= raise_condition(cond->get_sql_errno(),
+                                           cond->get_sqlstate(),
+                                           cond->get_level(),
+                                           *cond/*Sql_user_condition_identity*/,
+                                           cond->get_message_text());
+    if (raised)
+      raised->copy_opt_attributes(cond);
+    return raised;
+  }
+
 public:
   /** Overloaded to guard query/query_length fields */
   virtual void set_statement(Statement *stmt);
diff --git a/sql/sql_error.cc b/sql/sql_error.cc
index 2e9b1dabea4..745471a1365 100644
--- a/sql/sql_error.cc
+++ b/sql/sql_error.cc
@@ -307,7 +307,8 @@ Diagnostics_area::reset_diagnostics_area()
   m_can_overwrite_status= FALSE;
   /** Don't take chances in production */
   m_message[0]= '\0';
-  m_sql_errno= 0;
+  Sql_state_errno::clear();
+  Sql_user_condition_identity::clear();
   m_affected_rows= 0;
   m_last_insert_id= 0;
   m_statement_warn_count= 0;
@@ -406,6 +407,7 @@ Diagnostics_area::set_error_status(uint sql_errno)
   set_error_status(sql_errno,
                    ER(sql_errno),
                    mysql_errno_to_sqlstate(sql_errno),
+                   Sql_user_condition_identity(),
                    NULL);
 }
 
@@ -419,6 +421,7 @@ Diagnostics_area::set_error_status(uint sql_errno)
   @param sql_errno        SQL-condition error number
   @param message          SQL-condition message
   @param sqlstate         SQL-condition state
+  @param ucid             User defined condition identity
   @param error_condition  SQL-condition object representing the error state
 
   @note Note, that error_condition may be NULL. It happens if a) OOM error is
@@ -429,6 +432,7 @@ void
 Diagnostics_area::set_error_status(uint sql_errno,
                                    const char *message,
                                    const char *sqlstate,
+                                   const Sql_user_condition_identity &ucid,
                                    const Sql_condition *error_condition)
 {
   DBUG_ENTER("set_error_status");
@@ -455,7 +459,8 @@ Diagnostics_area::set_error_status(uint sql_errno,
     return;
 #endif
 
-  set_condition_value(sql_errno, sqlstate);
+  Sql_state_errno::set(sql_errno, sqlstate);
+  Sql_user_condition_identity::set(ucid);
   strmake_buf(m_message, message);
 
   get_warning_info()->set_error_condition(error_condition);
@@ -647,7 +652,7 @@ void Warning_info::reserve_space(THD *thd, uint count)
 }
 
 Sql_condition *Warning_info::push_warning(THD *thd,
-                                          const Sql_state_errno_level *value,
+                                          const Sql_condition_identity *value,
                                           const char *msg)
 {
   Sql_condition *cond= NULL;
@@ -657,7 +662,7 @@ Sql_condition *Warning_info::push_warning(THD *thd,
     if (m_allow_unlimited_warnings ||
         m_warn_list.elements() < thd->variables.max_error_count)
     {
-      cond= new (& m_warn_root) Sql_condition(& m_warn_root, value, msg);
+      cond= new (& m_warn_root) Sql_condition(& m_warn_root, *value, msg);
       if (cond)
         m_warn_list.push_back(cond);
     }
diff --git a/sql/sql_error.h b/sql/sql_error.h
index d80ce218769..bbe97333210 100644
--- a/sql/sql_error.h
+++ b/sql/sql_error.h
@@ -27,6 +27,7 @@
 
 class THD;
 class my_decimal;
+class sp_condition_value;
 
 ///////////////////////////////////////////////////////////////////////////
 
@@ -130,15 +131,11 @@ public:
   uint get_sql_errno() const
   { return m_sql_errno; }
 
-  void set_condition_value(uint sql_errno, const char *sqlstate)
+  void set(uint sql_errno, const char *sqlstate)
   {
     m_sql_errno= sql_errno;
     set_sqlstate(sqlstate);
   }
-  void set_condition_value(const Sql_state_errno *other)
-  {
-    *this= *other;
-  }
   void clear()
   {
     m_sql_errno= 0;
@@ -194,6 +191,88 @@ public:
 };
 
 
+/*
+  class Sql_user_condition_identity.
+  Instances of this class uniquely idetify user defined conditions (EXCEPTION).
+
+    SET sql_mode=ORACLE;
+    CREATE PROCEDURE p1
+    AS
+      a EXCEPTION;
+    BEGIN
+      RAISE a;
+    EXCEPTION
+      WHEN a THEN NULL;
+    END;
+
+  Currently a user defined condition is identified by a pointer to
+  its parse time sp_condition_value instance. This can change when
+  we add packages. See MDEV-10591.
+*/
+class Sql_user_condition_identity
+{
+protected:
+  const sp_condition_value *m_user_condition_value;
+public:
+  Sql_user_condition_identity()
+   :m_user_condition_value(NULL)
+  { }
+  Sql_user_condition_identity(const sp_condition_value *value)
+   :m_user_condition_value(value)
+  { }
+  const sp_condition_value *get_user_condition_value() const
+  { return m_user_condition_value; }
+
+  void set(const Sql_user_condition_identity &identity)
+  {
+    *this= identity;
+  }
+  void clear()
+  {
+    m_user_condition_value= NULL;
+  }
+};
+
+
+/**
+  class Sql_condition_identity.
+  Instances of this class uniquely identify conditions
+  (including user-defined exceptions for sql_mode=ORACLE)
+  and store everything that is needed for handler search
+  purposes in sp_pcontext::find_handler().
+*/
+class Sql_condition_identity: public Sql_state_errno_level,
+                              public Sql_user_condition_identity
+{
+public:
+  Sql_condition_identity()
+  { }
+  Sql_condition_identity(const Sql_state_errno_level &st,
+                         const Sql_user_condition_identity &ucid)
+   :Sql_state_errno_level(st),
+    Sql_user_condition_identity(ucid)
+  { }
+  Sql_condition_identity(const Sql_state_errno &st,
+                         enum_warning_level level,
+                         const Sql_user_condition_identity &ucid)
+   :Sql_state_errno_level(st, level),
+    Sql_user_condition_identity(ucid)
+  { }
+  Sql_condition_identity(uint sqlerrno,
+                         const char* sqlstate,
+                         enum_warning_level level,
+                         const Sql_user_condition_identity &ucid)
+    :Sql_state_errno_level(sqlerrno, sqlstate, level),
+     Sql_user_condition_identity(ucid)
+  { }
+  void clear()
+  {
+    Sql_state_errno_level::clear();
+    Sql_user_condition_identity::clear();
+  }
+};
+
+
 class Sql_condition_items
 {
 protected:
@@ -262,7 +341,7 @@ protected:
   or an exception condition (error, not found).
 */
 class Sql_condition : public Sql_alloc,
-                      public Sql_state_errno_level,
+                      public Sql_condition_identity,
                       public Sql_condition_items
 {
 public:
@@ -342,6 +421,12 @@ private:
     DBUG_ASSERT(mem_root != NULL);
   }
 
+  Sql_condition(MEM_ROOT *mem_root, const Sql_user_condition_identity &ucid)
+   :Sql_condition_identity(Sql_state_errno_level(), ucid),
+    m_mem_root(mem_root)
+  {
+    DBUG_ASSERT(mem_root != NULL);
+  }
   /**
     Constructor for a fixed message text.
     @param mem_root - memory root
@@ -350,25 +435,13 @@ private:
     @param msg      - the message text for this condition
   */
   Sql_condition(MEM_ROOT *mem_root,
-                const Sql_state_errno_level *value,
+                const Sql_condition_identity &value,
                 const char *msg)
-   :Sql_state_errno_level(*value),
+   :Sql_condition_identity(value),
     m_mem_root(mem_root)
   {
     DBUG_ASSERT(mem_root != NULL);
-    DBUG_ASSERT(value->get_sql_errno() != 0);
-    DBUG_ASSERT(msg != NULL);
-    set_builtin_message_text(msg);
-  }
-
-  Sql_condition(MEM_ROOT *mem_root,
-                const Sql_state_errno *value,
-                const char *msg)
-   :Sql_state_errno_level(*value, Sql_condition::WARN_LEVEL_ERROR),
-    m_mem_root(mem_root)
-  {
-    DBUG_ASSERT(mem_root != NULL);
-    DBUG_ASSERT(value->get_sql_errno() != 0);
+    DBUG_ASSERT(value.get_sql_errno() != 0);
     DBUG_ASSERT(msg != NULL);
     set_builtin_message_text(msg);
   }
@@ -409,7 +482,7 @@ private:
   */
   void clear()
   {
-    Sql_state_errno_level::clear();
+    Sql_condition_identity::clear();
     Sql_condition_items::clear();
     m_message_text.length(0);
   }
@@ -664,15 +737,13 @@ private:
     counters.
 
     @param thd        Thread context.
-    @param sql_errno  SQL-condition error number.
-    @param sqlstate   SQL-condition state.
-    @param level      SQL-condition level.
+    @param identity   SQL-condition identity
     @param msg        SQL-condition message.
 
     @return a pointer to the added SQL-condition.
   */
   Sql_condition *push_warning(THD *thd,
-                              const Sql_state_errno_level *value,
+                              const Sql_condition_identity *identity,
                               const char* msg);
 
   /**
@@ -829,7 +900,8 @@ public:
   Can not be assigned twice per statement.
 */
 
-class Diagnostics_area: public Sql_state_errno
+class Diagnostics_area: public Sql_state_errno,
+                        public Sql_user_condition_identity
 {
 private:
   /** The type of the counted and doubly linked list of conditions. */
@@ -881,8 +953,19 @@ public:
   void set_error_status(uint sql_errno,
                         const char *message,
                         const char *sqlstate,
+                        const Sql_user_condition_identity &ucid,
                         const Sql_condition *error_condition);
 
+  void set_error_status(uint sql_errno,
+                        const char *message,
+                        const char *sqlstate,
+                        const Sql_condition *error_condition)
+  {
+    set_error_status(sql_errno, message, sqlstate,
+                     Sql_user_condition_identity(),
+                     error_condition);
+  }
+
   void disable_status();
 
   void reset_diagnostics_area();
@@ -944,6 +1027,18 @@ public:
     return m_statement_warn_count;
   }
 
+  /**
+    Get the current errno, state and id of the user defined condition
+    and return them as Sql_condition_identity.
+  */
+  Sql_condition_identity get_error_condition_identity() const
+  {
+    DBUG_ASSERT(m_status == DA_ERROR);
+    return Sql_condition_identity(*this /*Sql_state_errno*/,
+                                  Sql_condition::WARN_LEVEL_ERROR,
+                                  *this /*Sql_user_condition_identity*/);
+  }
+
   /* Used to count any warnings pushed after calling set_ok_status(). */
   void increment_warning()
   {
@@ -1040,12 +1135,22 @@ public:
                               uint sql_errno_arg,
                               const char* sqlstate,
                               Sql_condition::enum_warning_level level,
+                              const Sql_user_condition_identity &ucid,
                               const char* msg)
   {
-    Sql_state_errno_level tmp(sql_errno_arg, sqlstate, level);
+    Sql_condition_identity tmp(sql_errno_arg, sqlstate, level, ucid);
     return get_warning_info()->push_warning(thd, &tmp, msg);
   }
 
+  Sql_condition *push_warning(THD *thd,
+                              uint sqlerrno,
+                              const char* sqlstate,
+                              Sql_condition::enum_warning_level level,
+                              const char* msg)
+  {
+    return push_warning(thd, sqlerrno, sqlstate, level,
+                        Sql_user_condition_identity(), msg);
+  }
   void mark_sql_conditions_for_removal()
   { get_warning_info()->mark_sql_conditions_for_removal(); }
 
diff --git a/sql/sql_signal.cc b/sql/sql_signal.cc
index a4a31207a7d..828149f3035 100644
--- a/sql/sql_signal.cc
+++ b/sql/sql_signal.cc
@@ -353,13 +353,7 @@ bool Sql_cmd_common_signal::raise_condition(THD *thd, Sql_condition *cond)
   DBUG_ASSERT((cond->m_level == Sql_condition::WARN_LEVEL_WARN) ||
               (cond->m_level == Sql_condition::WARN_LEVEL_ERROR));
 
-  Sql_condition *raised= NULL;
-  raised= thd->raise_condition(cond->get_sql_errno(),
-                               cond->get_sqlstate(),
-                               cond->get_level(),
-                               cond->get_message_text());
-  if (raised)
-    raised->copy_opt_attributes(cond);
+  (void) thd->raise_condition(cond);
 
   if (cond->m_level == Sql_condition::WARN_LEVEL_WARN)
   {
@@ -373,7 +367,8 @@ bool Sql_cmd_common_signal::raise_condition(THD *thd, Sql_condition *cond)
 bool Sql_cmd_signal::execute(THD *thd)
 {
   bool result= TRUE;
-  Sql_condition cond(thd->mem_root);
+  DBUG_ASSERT(m_cond);
+  Sql_condition cond(thd->mem_root, m_cond->get_user_condition_identity());
 
   DBUG_ENTER("Sql_cmd_signal::execute");
 
@@ -427,7 +422,7 @@ bool Sql_cmd_resignal::execute(THD *thd)
     DBUG_RETURN(result);
   }
 
-  Sql_condition signaled_err(thd->mem_root, signaled, signaled->message);
+  Sql_condition signaled_err(thd->mem_root, *signaled, signaled->message);
 
   if (m_cond)
   {
diff --git a/sql/sql_yacc_ora.yy b/sql/sql_yacc_ora.yy
index 9ddadee5ffd..db1a20e110b 100644
--- a/sql/sql_yacc_ora.yy
+++ b/sql/sql_yacc_ora.yy
@@ -2416,6 +2416,16 @@ sp_decl_body:
             $$.vars= $$.hndlrs= $$.curs= 0;
             $$.conds= 1;
           }
+        | ident_directly_assignable EXCEPTION_SYM
+          {
+            sp_condition_value *spcond= new (thd->mem_root)
+                                        sp_condition_value_user_defined();
+            if (!spcond ||
+                Lex->spcont->declare_condition(thd, $1, spcond))
+              MYSQL_YYABORT;
+            $$.vars= $$.hndlrs= $$.curs= 0;
+            $$.conds= 1;
+          }
         | sp_handler_type HANDLER_SYM FOR_SYM
           {
             if (Lex->sp_handler_declaration_init(thd, $1))