postgres.git / summary / log / commit / refs
commit 89ef2aedae448cc51cd7bf7c81d56a08d1da7467
Author: Tom Lane <tgl@sss.pgh.pa.us>
Date: Tue Jun 04 22:02:13 2024 +0000
First released in: 17.0, 12.20, 13.16, 14.13, 15.8, 16.4
Fix pl/tcl's handling of errors from Tcl_ListObjGetElements().
In a procedure or function returning tuple, we use that function to
parse the Tcl script's result, which is supposed to be a Tcl list.
If it isn't, you get an error. Commit 26abb50c4 incautiously
supposed that we could use throw_tcl_error() to report such an error.
That doesn't actually work, because low-level functions like
Tcl_ListObjGetElements() don't fill Tcl's errorInfo variable.
The result is either a null-pointer-dereference crash or emission
of misleading context information describing the previous Tcl error.
Back off to just reporting the interpreter's result string, and
improve throw_tcl_error()'s comment to explain when to use it.
Also, although the similar code in pltcl_trigger_handler() avoided
this mistake, it was using a fairly confusing wording of the
error message. Improve that while we're here.
Per report from A. Kozhemyakin. Back-patch to all supported
branches.
Erik Wienhold and Tom Lane
Discussion: https://postgr.es/m/6a2a1c40-2b2c-4a33-8b72-243c0766fcda@postgrespro.ru
src/pl/tcl/expected/pltcl_call.out | 8 ++++++++
src/pl/tcl/pltcl.c | 11 +++++++++--
src/pl/tcl/sql/pltcl_call.sql | 11 +++++++++++
3 files changed, 28 insertions(+), 2 deletions(-)
diff --git a/src/pl/tcl/expected/pltcl_call.out b/src/pl/tcl/expected/pltcl_call.out
index e4498375ec1..7bb5dffe5d7 100644
--- a/src/pl/tcl/expected/pltcl_call.out
+++ b/src/pl/tcl/expected/pltcl_call.out
@@ -66,6 +66,14 @@ END
$$;
NOTICE: a: 10
NOTICE: _a: 10, _b: 20
+-- syntax error in result tuple
+CREATE PROCEDURE test_proc10(INOUT a text)
+LANGUAGE pltcl
+AS $$
+return [list a {$a + $a}])
+$$;
+CALL test_proc10('abc');
+ERROR: could not parse function return value: list element in braces followed by ")" instead of space
DROP PROCEDURE test_proc1;
DROP PROCEDURE test_proc2;
DROP PROCEDURE test_proc3;
diff --git a/src/pl/tcl/pltcl.c b/src/pl/tcl/pltcl.c
index 11f1ff19139..ecf54b98942 100644
--- a/src/pl/tcl/pltcl.c
+++ b/src/pl/tcl/pltcl.c
@@ -1027,7 +1027,10 @@ pltcl_func_handler(PG_FUNCTION_ARGS, pltcl_call_state *call_state,
/* Convert function result to tuple */
resultObj = Tcl_GetObjResult(interp);
if (Tcl_ListObjGetElements(interp, resultObj, &resultObjc, &resultObjv) == TCL_ERROR)
- throw_tcl_error(interp, prodesc->user_proname);
+ ereport(ERROR,
+ (errcode(ERRCODE_EXTERNAL_ROUTINE_EXCEPTION),
+ errmsg("could not parse function return value: %s",
+ utf_u2e(Tcl_GetStringResult(interp)))));
tup = pltcl_build_tuple_result(interp, resultObjv, resultObjc,
call_state);
@@ -1293,7 +1296,7 @@ pltcl_trigger_handler(PG_FUNCTION_ARGS, pltcl_call_state *call_state,
&result_Objc, &result_Objv) != TCL_OK)
ereport(ERROR,
(errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
- errmsg("could not split return value from trigger: %s",
+ errmsg("could not parse trigger return value: %s",
utf_u2e(Tcl_GetStringResult(interp)))));
/* Convert function result to tuple */
@@ -1356,6 +1359,10 @@ pltcl_event_trigger_handler(PG_FUNCTION_ARGS, pltcl_call_state *call_state,
/**********************************************************************
* throw_tcl_error - ereport an error returned from the Tcl interpreter
+ *
+ * Caution: use this only to report errors returned by Tcl_EvalObjEx() or
+ * other variants of Tcl_Eval(). Other functions may not fill "errorInfo",
+ * so it could be unset or even contain details from some previous error.
**********************************************************************/
static void
throw_tcl_error(Tcl_Interp *interp, const char *proname)
diff --git a/src/pl/tcl/sql/pltcl_call.sql b/src/pl/tcl/sql/pltcl_call.sql
index 37efbdefc23..fe64361c732 100644
--- a/src/pl/tcl/sql/pltcl_call.sql
+++ b/src/pl/tcl/sql/pltcl_call.sql
@@ -71,6 +71,17 @@ END
$$;
+-- syntax error in result tuple
+
+CREATE PROCEDURE test_proc10(INOUT a text)
+LANGUAGE pltcl
+AS $$
+return [list a {$a + $a}])
+$$;
+
+CALL test_proc10('abc');
+
+
DROP PROCEDURE test_proc1;
DROP PROCEDURE test_proc2;
DROP PROCEDURE test_proc3;
[parent: 6b52e2298d85]