Fixed BUG#8408: Stored procedure crash if function contains SHOW

  We simply have to disallow any kind of result set being sent back
  from a function. Can't see any way to make that to work.


mysql-test/r/sp-error.result:
  New test case for BUG#8408.
mysql-test/t/sp-error.test:
  New test case for BUG#8408.
sql/item_func.cc:
  Disable result sets from functions but temporarily turning CLIENT_MULTI_RESULTS off.
sql/share/errmsg.txt:
  Added error message for statements not allowed in functions (detected during parsing).
sql/sql_yacc.yy:
  Don't allow result sets in functions.

mysql-test/r/sp-error.result

@@ -594,4 +594,52 @@ alter function bug7047;
 return 0;
 end|
 ERROR HY000: Can't drop or alter a FUNCTION from within another stored routine
+drop function if exists bug8408|
+drop procedure if exists bug8408|
+create function bug8408() returns int
+begin
+select * from t1;
+return 0;
+end|
+ERROR 0A000: Not allowed to return a result set from a function
+create function bug8408() returns int
+begin
+show warnings;
+return 0;
+end|
+ERROR 0A000: Not allowed to return a result set from a function
+create function bug8408(a int) returns int
+begin
+declare b int;
+select b;
+return b;
+end|
+ERROR 0A000: Not allowed to return a result set from a function
+create function bug8408() returns int
+begin
+call bug8408();
+return 0;
+end|
+create procedure bug8408()
+select * from t1|
+call bug8408()|
+val	x
+select bug8408()|
+ERROR 0A000: SELECT in a stored procedure must have INTO
+drop procedure bug8408|
+drop function bug8408|
+create function bug8408() returns int
+begin
+declare n int default 0;
+select count(*) into n from t1;
+return n;
+end|
+insert into t1 value (2, 2.7), (3, 3.14), (7, 7.0)|
+select *,bug8408() from t1|
+val	x	bug8408()
+2	2.7	3
+3	3.14	3
+7	7	3
+drop function bug8408|
+delete from t1|
 drop table t1|

mysql-test/t/sp-error.test

@@ -831,6 +831,67 @@ begin
 end|
 
 
+#
+# BUG#8408: Stored procedure crash if function contains SHOW
+# BUG#9058: Stored Procedures: Crash if function included SELECT
+#
+--disable_warnings
+drop function if exists bug8408|
+drop procedure if exists bug8408|
+--enable_warnings
+
+# Some things are caught when parsing
+--error ER_SP_NO_RETSET_IN_FUNC
+create function bug8408() returns int
+begin
+  select * from t1;
+  return 0;
+end|
+--error ER_SP_NO_RETSET_IN_FUNC
+create function bug8408() returns int
+begin
+  show warnings;
+  return 0;
+end|
+--error ER_SP_NO_RETSET_IN_FUNC
+create function bug8408(a int) returns int
+begin
+  declare b int;
+  select b;
+  return b;
+end|
+
+# Some things must be caught at invokation time
+create function bug8408() returns int
+begin
+  call bug8408();
+  return 0;
+end|
+create procedure bug8408()
+  select * from t1|
+
+call bug8408()|
+--error ER_SP_BADSELECT
+select bug8408()|
+
+drop procedure bug8408|
+drop function bug8408|
+
+# But this is ok
+create function bug8408() returns int
+begin
+  declare n int default 0;
+  select count(*) into n from t1;
+  return n;
+end|
+
+insert into t1 value (2, 2.7), (3, 3.14), (7, 7.0)|
+select *,bug8408() from t1|
+
+drop function bug8408|
+delete from t1|
+
+
 #
 # BUG#NNNN: New bug synopsis
 #

sql/item_func.cc

@@ -4554,6 +4554,7 @@ Item_func_sp::execute(Item **itp)
 {
   DBUG_ENTER("Item_func_sp::execute");
   THD *thd= current_thd;
+  bool clcap_mr;
   int res;
 #ifndef NO_EMBEDDED_ACCESS_CHECKS
   st_sp_security_context save_ctx;
@@ -4567,6 +4568,9 @@ Item_func_sp::execute(Item **itp)
     DBUG_RETURN(-1);
   }
 
+  clcap_mr= (thd->client_capabilities & CLIENT_MULTI_RESULTS);
+  thd->client_capabilities &= ~CLIENT_MULTI_RESULTS;
+
 #ifndef EMBEDDED_LIBRARY
   my_bool nsok= thd->net.no_send_ok;
   thd->net.no_send_ok= TRUE;
@@ -4582,6 +4586,8 @@ Item_func_sp::execute(Item **itp)
 			     m_sp->m_db.str, m_sp->m_name.str, 0))
   {
     sp_restore_security_context(thd, m_sp, &save_ctx);
+    if (clcap_mr)
+      thd->client_capabilities |= CLIENT_MULTI_RESULTS;
     DBUG_RETURN(-1);
   }
 #endif
@@ -4595,6 +4601,10 @@ Item_func_sp::execute(Item **itp)
 #ifndef EMBEDDED_LIBRARY
   thd->net.no_send_ok= nsok;
 #endif
+
+  if (clcap_mr)
+    thd->client_capabilities |= CLIENT_MULTI_RESULTS;
+
   DBUG_RETURN(res);
 }
 

sql/share/errmsg.txt

@@ -5342,3 +5342,5 @@ ER_SP_DUP_HANDLER 42000
 	eng "Duplicate handler declared in the same block"
 ER_SP_NOT_VAR_ARG 42000
 	eng "OUT or INOUT argument %d for routine %s is not a variable"
+ER_SP_NO_RETSET_IN_FUNC 0A000
+	eng "Not allowed to return a result set from a function"

sql/sql_yacc.yy

@@ -1442,6 +1442,12 @@ create_function_tail:
 	    LEX *lex= Lex;
 	    sp_head *sp= lex->sphead;
 
+	    if (sp->m_multi_results)
+	    {
+	      my_message(ER_SP_NO_RETSET_IN_FUNC, ER(ER_SP_NO_RETSET_IN_FUNC),
+	                 MYF(0));
+	      YYABORT;
+	    }
 	    if (sp->check_backpatch(YYTHD))
 	      YYABORT;
 	    lex->sql_command= SQLCOM_CREATE_SPFUNCTION;