Check that a FUNCTION contains RETURN and that we actually get a return value.

include/mysqld_error.h:
  New error codes/messages for missing RETURNs in FUNCTIONs.
mysql-test/r/sp-error.result:
  New error tests for missing RETURNs in FUNCTIONs.
mysql-test/t/sp-error.test:
  New error tests for missing RETURNs in FUNCTIONs.
sql/share/czech/errmsg.txt:
  New error codes/messages for missing RETURNs in FUNCTIONs.
sql/share/danish/errmsg.txt:
  New error codes/messages for missing RETURNs in FUNCTIONs.
sql/share/dutch/errmsg.txt:
  New error codes/messages for missing RETURNs in FUNCTIONs.
sql/share/english/errmsg.txt:
  New error codes/messages for missing RETURNs in FUNCTIONs.
sql/share/estonian/errmsg.txt:
  New error codes/messages for missing RETURNs in FUNCTIONs.
sql/share/french/errmsg.txt:
  New error codes/messages for missing RETURNs in FUNCTIONs.
sql/share/german/errmsg.txt:
  New error codes/messages for missing RETURNs in FUNCTIONs.
sql/share/greek/errmsg.txt:
  New error codes/messages for missing RETURNs in FUNCTIONs.
sql/share/hungarian/errmsg.txt:
  New error codes/messages for missing RETURNs in FUNCTIONs.
sql/share/italian/errmsg.txt:
  New error codes/messages for missing RETURNs in FUNCTIONs.
sql/share/japanese/errmsg.txt:
  New error codes/messages for missing RETURNs in FUNCTIONs.
sql/share/korean/errmsg.txt:
  New error codes/messages for missing RETURNs in FUNCTIONs.
sql/share/norwegian-ny/errmsg.txt:
  New error codes/messages for missing RETURNs in FUNCTIONs.
sql/share/norwegian/errmsg.txt:
  New error codes/messages for missing RETURNs in FUNCTIONs.
sql/share/polish/errmsg.txt:
  New error codes/messages for missing RETURNs in FUNCTIONs.
sql/share/portuguese/errmsg.txt:
  New error codes/messages for missing RETURNs in FUNCTIONs.
sql/share/romanian/errmsg.txt:
  New error codes/messages for missing RETURNs in FUNCTIONs.
sql/share/russian/errmsg.txt:
  New error codes/messages for missing RETURNs in FUNCTIONs.
sql/share/serbian/errmsg.txt:
  New error codes/messages for missing RETURNs in FUNCTIONs.
sql/share/slovak/errmsg.txt:
  New error codes/messages for missing RETURNs in FUNCTIONs.
sql/share/spanish/errmsg.txt:
  New error codes/messages for missing RETURNs in FUNCTIONs.
sql/share/swedish/errmsg.txt:
  New error codes/messages for missing RETURNs in FUNCTIONs.
sql/share/ukrainian/errmsg.txt:
  New error codes/messages for missing RETURNs in FUNCTIONs.
sql/sp_head.h:
  Check that a FUNCTION contains RETURN.
sql/sql_parse.cc:
  Check that a FUNCTION contains RETURN.
sql/sql_yacc.yy:
  Check that a FUNCTION contains RETURN.

include/mysqld_error.h

@@ -312,4 +312,6 @@
 #define ER_QUERY_INTERRUPTED 1293
 #define ER_SP_WRONG_NO_OF_ARGS 1294
 #define ER_SP_COND_MISMATCH 1295
-#define ER_ERROR_MESSAGES 296
+#define ER_SP_NORETURN 1296
+#define ER_SP_NORETURNEND 1297
+#define ER_ERROR_MESSAGES 298

mysql-test/r/sp-error.result

@@ -121,3 +121,20 @@ set res = 1;
 end if;
 end;
 ERROR HY000: Undefined CONDITION: bar
+create function f(val int) returns int
+begin
+declare x int;
+set x = val+3;
+end;
+ERROR HY000: No RETURN found in FUNCTION f
+create function f(val int) returns int
+begin
+declare x int;
+set x = val+3;
+if x < 4 then
+return x;
+end if;
+end;
+select f(10);
+ERROR HY000: FUNCTION f ended without RETURN
+drop function f;

mysql-test/t/sp-error.test

@@ -171,4 +171,27 @@ begin
   end if;
 end|
 
+--error 1296
+create function f(val int) returns int
+begin
+  declare x int;
+
+  set x = val+3;
+end|
+
+create function f(val int) returns int
+begin
+  declare x int;
+
+  set x = val+3;
+  if x < 4 then
+    return x;
+  end if;
+end|
+
+--error 1297
+select f(10)|
+
+drop function f|
+
 delimiter ;|

sql/share/czech/errmsg.txt

@@ -308,3 +308,5 @@ character-set=latin2
 "Query execution was interrupted"
 "Wrong number of arguments for %s %s, expected %u, got %u"
 "Undefined CONDITION: %s"
+"No RETURN found in FUNCTION %s"
+"FUNCTION %s ended without RETURN"

sql/share/danish/errmsg.txt

@@ -302,3 +302,5 @@ character-set=latin1
 "Query execution was interrupted"
 "Wrong number of arguments for %s %s, expected %u, got %u"
 "Undefined CONDITION: %s"
+"No RETURN found in FUNCTION %s"
+"FUNCTION %s ended without RETURN"

sql/share/dutch/errmsg.txt

@@ -310,3 +310,5 @@ character-set=latin1
 "Query execution was interrupted"
 "Wrong number of arguments for %s %s, expected %u, got %u"
 "Undefined CONDITION: %s"
+"No RETURN found in FUNCTION %s"
+"FUNCTION %s ended without RETURN"

sql/share/english/errmsg.txt

@@ -299,3 +299,5 @@ character-set=latin1
 "Query execution was interrupted"
 "Wrong number of arguments for %s %s, expected %u, got %u"
 "Undefined CONDITION: %s"
+"No RETURN found in FUNCTION %s"
+"FUNCTION %s ended without RETURN"

sql/share/estonian/errmsg.txt

@@ -304,3 +304,5 @@ character-set=latin7
 "Query execution was interrupted"
 "Wrong number of arguments for %s %s, expected %u, got %u"
 "Undefined CONDITION: %s"
+"No RETURN found in FUNCTION %s"
+"FUNCTION %s ended without RETURN"

sql/share/french/errmsg.txt

@@ -299,3 +299,5 @@ character-set=latin1
 "Query execution was interrupted"
 "Wrong number of arguments for %s %s, expected %u, got %u"
 "Undefined CONDITION: %s"
+"No RETURN found in FUNCTION %s"
+"FUNCTION %s ended without RETURN"

sql/share/german/errmsg.txt

@@ -308,3 +308,5 @@ character-set=latin1
 "Query execution was interrupted"
 "Wrong number of arguments for %s %s, expected %u, got %u"
 "Undefined CONDITION: %s"
+"No RETURN found in FUNCTION %s"
+"FUNCTION %s ended without RETURN"

sql/share/greek/errmsg.txt

@@ -299,3 +299,5 @@ character-set=greek
 "Query execution was interrupted"
 "Wrong number of arguments for %s %s, expected %u, got %u"
 "Undefined CONDITION: %s"
+"No RETURN found in FUNCTION %s"
+"FUNCTION %s ended without RETURN"

sql/share/hungarian/errmsg.txt

@@ -301,3 +301,5 @@ character-set=latin2
 "Query execution was interrupted"
 "Wrong number of arguments for %s %s, expected %u, got %u"
 "Undefined CONDITION: %s"
+"No RETURN found in FUNCTION %s"
+"FUNCTION %s ended without RETURN"

sql/share/italian/errmsg.txt

@@ -299,3 +299,5 @@ character-set=latin1
 "Query execution was interrupted"
 "Wrong number of arguments for %s %s, expected %u, got %u"
 "Undefined CONDITION: %s"
+"No RETURN found in FUNCTION %s"
+"FUNCTION %s ended without RETURN"

sql/share/japanese/errmsg.txt

@@ -301,3 +301,5 @@ character-set=ujis
 "Query execution was interrupted"
 "Wrong number of arguments for %s %s, expected %u, got %u"
 "Undefined CONDITION: %s"
+"No RETURN found in FUNCTION %s"
+"FUNCTION %s ended without RETURN"

sql/share/korean/errmsg.txt

@@ -299,3 +299,5 @@ character-set=euckr
 "Query execution was interrupted"
 "Wrong number of arguments for %s %s, expected %u, got %u"
 "Undefined CONDITION: %s"
+"No RETURN found in FUNCTION %s"
+"FUNCTION %s ended without RETURN"

sql/share/norwegian-ny/errmsg.txt

@@ -301,3 +301,5 @@ character-set=latin1
 "Query execution was interrupted"
 "Wrong number of arguments for %s %s, expected %u, got %u"
 "Undefined CONDITION: %s"
+"No RETURN found in FUNCTION %s"
+"FUNCTION %s ended without RETURN"

sql/share/norwegian/errmsg.txt

@@ -301,3 +301,5 @@ character-set=latin1
 "Query execution was interrupted"
 "Wrong number of arguments for %s %s, expected %u, got %u"
 "Undefined CONDITION: %s"
+"No RETURN found in FUNCTION %s"
+"FUNCTION %s ended without RETURN"

sql/share/polish/errmsg.txt

@@ -303,3 +303,5 @@ character-set=latin2
 "Query execution was interrupted"
 "Wrong number of arguments for %s %s, expected %u, got %u"
 "Undefined CONDITION: %s"
+"No RETURN found in FUNCTION %s"
+"FUNCTION %s ended without RETURN"

sql/share/portuguese/errmsg.txt

@@ -300,3 +300,5 @@ character-set=latin1
 "Query execution was interrupted"
 "Wrong number of arguments for %s %s, expected %u, got %u"
 "Undefined CONDITION: %s"
+"No RETURN found in FUNCTION %s"
+"FUNCTION %s ended without RETURN"

sql/share/romanian/errmsg.txt

@@ -303,3 +303,5 @@ character-set=latin2
 "Query execution was interrupted"
 "Wrong number of arguments for %s %s, expected %u, got %u"
 "Undefined CONDITION: %s"
+"No RETURN found in FUNCTION %s"
+"FUNCTION %s ended without RETURN"

sql/share/russian/errmsg.txt

@@ -301,3 +301,5 @@ character-set=koi8r
 "Query execution was interrupted"
 "Wrong number of arguments for %s %s, expected %u, got %u"
 "Undefined CONDITION: %s"
+"No RETURN found in FUNCTION %s"
+"FUNCTION %s ended without RETURN"

sql/share/serbian/errmsg.txt

@@ -294,3 +294,5 @@ character-set=cp1250
 "Query execution was interrupted"
 "Wrong number of arguments for %s %s, expected %u, got %u"
 "Undefined CONDITION: %s"
+"No RETURN found in FUNCTION %s"
+"FUNCTION %s ended without RETURN"

sql/share/slovak/errmsg.txt

@@ -307,3 +307,5 @@ character-set=latin2
 "Query execution was interrupted"
 "Wrong number of arguments for %s %s, expected %u, got %u"
 "Undefined CONDITION: %s"
+"No RETURN found in FUNCTION %s"
+"FUNCTION %s ended without RETURN"

sql/share/spanish/errmsg.txt

@@ -301,3 +301,5 @@ character-set=latin1
 "Query execution was interrupted"
 "Wrong number of arguments for %s %s, expected %u, got %u"
 "Undefined CONDITION: %s"
+"No RETURN found in FUNCTION %s"
+"FUNCTION %s ended without RETURN"

sql/share/swedish/errmsg.txt

@@ -299,3 +299,5 @@ character-set=latin1
 "Query execution was interrupted"
 "Wrong number of arguments for %s %s, expected %u, got %u"
 "Undefined CONDITION: %s"
+"No RETURN found in FUNCTION %s"
+"FUNCTION %s ended without RETURN"

sql/share/ukrainian/errmsg.txt

@@ -304,3 +304,5 @@ character-set=koi8u
 "Query execution was interrupted"
 "Wrong number of arguments for %s %s, expected %u, got %u"
 "Undefined CONDITION: %s"
+"No RETURN found in FUNCTION %s"
+"FUNCTION %s ended without RETURN"

sql/sp_head.cc

@@ -120,7 +120,8 @@ sp_head::operator delete(void *ptr, size_t size)
 }
 
 sp_head::sp_head()
-  : Sql_alloc(), m_simple_case(FALSE), m_multi_results(FALSE), m_free_list(NULL)
+  : Sql_alloc(), m_has_return(FALSE), m_simple_case(FALSE),
+    m_multi_results(FALSE), m_free_list(NULL)
 {
   DBUG_ENTER("sp_head::sp_head");
 
@@ -321,7 +322,18 @@ sp_head::execute_function(THD *thd, Item **argp, uint argcount, Item **resp)
 
   ret= execute(thd);
   if (ret == 0)
-    *resp= nctx->get_result();
+  {
+    Item *it= nctx->get_result();
+
+    if (it)
+      *resp= it;
+    else
+    {
+      my_printf_error(ER_SP_NORETURNEND, ER(ER_SP_NORETURNEND), MYF(0),
+		      m_name.str);
+      ret= -1;
+    }
+  }
 
   thd->spcont= octx;
   DBUG_RETURN(ret);

sql/sp_head.h

@@ -47,6 +47,7 @@ class sp_head : public Sql_alloc
 
   int m_type;			// TYPE_ENUM_FUNCTION or TYPE_ENUM_PROCEDURE
   enum enum_field_types m_returns; // For FUNCTIONs only
+  my_bool m_has_return;		// For FUNCTIONs only
   my_bool m_simple_case;	// TRUE if parsing simple case, FALSE otherwise
   my_bool m_multi_results;	// TRUE if a procedure with SELECT(s)
   uint m_old_cmq;		// Old CLIENT_MULTI_QUERIES value

sql/sql_parse.cc

@@ -3226,6 +3226,13 @@ mysql_execute_command(THD *thd)
 	}
       }
 #endif
+      if (lex->sphead->m_type == TYPE_ENUM_FUNCTION &&
+	  !lex->sphead->m_has_return)
+      {
+	net_printf(thd, ER_SP_NORETURN, name);
+	goto error;
+      }
+
       res= lex->sphead->create(thd);
 
       switch (res)

sql/sql_yacc.yy

@@ -1424,6 +1424,7 @@ sp_proc_stmt:
 		                     $2, lex->sphead->m_returns);
 
 	      lex->sphead->add_instr(i);
+	      lex->sphead->m_has_return= TRUE;
 	    }
 	  }
 	| IF sp_if END IF {}