Bug #24736 | UDF functions parsed as Stored Functions | ||
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Submitted: | 30 Nov 2006 21:23 | Modified: | 11 Dec 2006 4:38 |
Reporter: | Marc ALFF | Email Updates: | |
Status: | Closed | Impact on me: | |
Category: | MySQL Server | Severity: | S1 (Critical) |
Version: | 5.1 | OS: | |
Assigned to: | Marc ALFF | CPU Architecture: | Any |
[30 Nov 2006 21:23]
Marc ALFF
[2 Dec 2006 2:16]
Bugs System
A patch for this bug has been committed. After review, it may be pushed to the relevant source trees for release in the next version. You can access the patch from: http://lists.mysql.com/commits/16346 ChangeSet@1.2399, 2006-12-01 19:16:03-07:00, malff@weblab.(none) +9 -0 Bug#24736: UDF functions parsed as Stored Functions Before this fix, a call to a User Defined Function (UDF) could, under some circumstances, be interpreted as a call to a Stored function instead. This occurred if a native function was invoked in the parameters for the UDF, as in "select my_udf(abs(x))". The root cause of this defect is the introduction, by the fix for Bug 21809, of st_select_lex::udf_list, and it's usage in the parser in sql_yacc.yy in the rule function_call_generic (in 5.1). While the fix itself for Bug 21809 is correct in 5.0, the code change merged into the 5.1 release created the issue, because the calls in 5.1 to : - lex->current_select->udf_list.push_front(udf) - lex->current_select->udf_list.pop() are not balanced in case of native functions, causing the udf_list, which is really a stack, to be out of sync with the internal stack maintained by the bison parser. Instead of moving the call to udf_list.pop(), which would have fixed the symptom, this patch goes further and removes the need for udf_list. This is motivated by two reasons: a) Maintaining a stack in the MySQL code in sync with the stack maintained internally in sql_yacc.cc (not .yy) is extremely dependent of the implementation of yacc/bison, and extremely difficult to maintain. It's also totally dependent of the structure of the grammar, and has a risk to break with regression defects each time the grammar itself is changed. b) The previous code did report construct like "foo(expr AS name)" as syntax errors (ER_PARSER_ERROR), which is incorrect, and misleading. The syntax is perfectly valid, as this expression is valid when "foo" is a UDF. Whether this syntax is legal or not depends of the semantic of "foo". With this change: a) There is only one stack (in bison), and no List<udf_func> to maintain. b) "foo(expr AS name)", when used incorrectly, is reported as semantic error: - ER_WRONG_PARAMETERS_TO_NATIVE_FCT (for native functions) - ER_WRONG_PARAMETERS_TO_STORED_FCT (for stored functions) This is achieved by the changes implemented in item_create.cc
[5 Dec 2006 16:12]
Mads Martin Joergensen
Daniel merged the fix to mysql-5.1
[11 Dec 2006 4:38]
Paul DuBois
Noted in 5.1.14 changelog. In some cases, a function that should be parsed as a user-defined function was parsed as a stored function.