Bug#28318 CREATE FUNCTION (UDF) requires a schema

Bug#29816 Syntactically wrong query fails with misleading error message

The core problem is that an SQL-invoked function name can be a <schema
qualified routine name> that contains no <schema name>, but the mysql
parser insists that all stored procedures (function, procedures and
triggers) must have a <schema name>, which is not true for functions.
This problem is especially visible when trying to create a function
or when a query contains a syntax error after a function call (in the
same query), both will fail with a "No database selected" message if
the session is not attached to a particular schema, but the first
one should succeed and the second fail with a "syntax error" message.

Part of the fix is to revamp the sp name handling so that a schema
name may be omitted for functions -- this means that the internal
function name representation may not have a dot, which represents
that the function doesn't have a schema name. The other part is
to place schema checks after the type (function, trigger or procedure)
of the routine is known.


mysql-test/r/sp-error.result:
  Add test case result for Bug#29816
mysql-test/r/udf.result:
  Add test case result for Bug#28318
mysql-test/t/sp-error.test:
  Add test case for Bug#29816
mysql-test/t/udf.test:
  Add test case for Bug#28318
sql/sp.cc:
  Copy the (last) nul byte of the stored routine key and move name parsing
  code to the sp_name class constructor.
sql/sp_head.cc:
  Revamp routine name parsing for when no schema is specified and
  omit dot from the qualified name if the routine is not associated
  with a scheme name.
sql/sp_head.h:
  Name parsing got bigger, uninline by moving to a single unit -- the sp_head.cc
  file.
sql/sql_yacc.yy:
  Only copy the schema name if one is actually set and check for schema
  name presence only where it's necessary.

1 files changed, 28 insertions, 3 deletions

diff --git a/sql/sp_head.cc b/sql/sp_head.cc
index 5ad6625efb8..69dda9ec1e8 100644
--- a/sql/sp_head.cc
+++ b/sql/sp_head.cc
@@ -369,17 +369,42 @@ sp_eval_expr(THD *thd, Field *result_field, Item **expr_item_ptr)
  *
  */
 
+sp_name::sp_name(THD *thd, char *key, uint key_len)
+{
+  m_sroutines_key.str= key;
+  m_sroutines_key.length= key_len;
+  m_qname.str= ++key;
+  m_qname.length= key_len - 1;
+  if ((m_name.str= strchr(m_qname.str, '.')))
+  {
+    m_db.length= m_name.str - key;
+    m_db.str= strmake_root(thd->mem_root, key, m_db.length);
+    m_name.str++;
+    m_name.length= m_qname.length - m_db.length - 1;
+  }
+  else
+  {
+    m_name.str= m_qname.str;
+    m_name.length= m_qname.length;
+    m_db.str= 0;
+    m_db.length= 0;
+  }
+  m_explicit_name= false;
+}
+
 void
 sp_name::init_qname(THD *thd)
 {
-  m_sroutines_key.length=  m_db.length + m_name.length + 2;
+  const uint dot= !!m_db.length;
+  /* m_sroutines format: m_type + [database + dot] + name + nul */
+  m_sroutines_key.length= 1 + m_db.length + dot + m_name.length;
   if (!(m_sroutines_key.str= thd->alloc(m_sroutines_key.length + 1)))
     return;
   m_qname.length= m_sroutines_key.length - 1;
   m_qname.str= m_sroutines_key.str + 1;
-  sprintf(m_qname.str, "%.*s.%.*s",
+  sprintf(m_qname.str, "%.*s%.*s%.*s",
 	  m_db.length, (m_db.length ? m_db.str : ""),
-	  m_name.length, m_name.str);
+          dot, ".", m_name.length, m_name.str);
 }