From 312ea93bfac03db7b1e5e72e173f272851ca57d0 Mon Sep 17 00:00:00 2001 From: Richard Guo Date: Tue, 13 May 2025 17:56:55 +0900 Subject: [PATCH v1] Fix Assert failure in XMLTABLE parser In an XMLTABLE expression, columns can be marked NOT NULL, and the parser internally fabricates an option named "is_not_null" to represent this. However, the parser also allows users to specify arbitrary option names. This creates a conflict: a user can explicitly use "is_not_null" as an option name and assign it a non-Boolean value, which violates internal assumptions and triggers an assertion failure. To fix, this patch checks whether a user-supplied name collides with the internally reserved option name and raises an error if so. Additionally, the internal name is renamed to "__pg__is_not_null" to further reduce the risk of collision with user-defined names. --- src/backend/parser/gram.y | 15 +++++++++++---- src/test/regress/expected/xml.out | 4 ++++ src/test/regress/expected/xml_1.out | 4 ++++ src/test/regress/expected/xml_2.out | 4 ++++ src/test/regress/sql/xml.sql | 2 ++ 5 files changed, 25 insertions(+), 4 deletions(-) diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index 3c4268b271a..0b5652071d1 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -14230,7 +14230,7 @@ xmltable_column_el: parser_errposition(defel->location))); fc->colexpr = defel->arg; } - else if (strcmp(defel->defname, "is_not_null") == 0) + else if (strcmp(defel->defname, "__pg__is_not_null") == 0) { if (nullability_seen) ereport(ERROR, @@ -14273,13 +14273,20 @@ xmltable_column_option_list: xmltable_column_option_el: IDENT b_expr - { $$ = makeDefElem($1, $2, @1); } + { + if (strcmp($1, "__pg__is_not_null") == 0) + ereport(ERROR, + (errcode(ERRCODE_SYNTAX_ERROR), + errmsg("option name \"%s\" cannot be used in XMLTABLE", $1), + parser_errposition(@1))); + $$ = makeDefElem($1, $2, @1); + } | DEFAULT b_expr { $$ = makeDefElem("default", $2, @1); } | NOT NULL_P - { $$ = makeDefElem("is_not_null", (Node *) makeBoolean(true), @1); } + { $$ = makeDefElem("__pg__is_not_null", (Node *) makeBoolean(true), @1); } | NULL_P - { $$ = makeDefElem("is_not_null", (Node *) makeBoolean(false), @1); } + { $$ = makeDefElem("__pg__is_not_null", (Node *) makeBoolean(false), @1); } | PATH b_expr { $$ = makeDefElem("path", $2, @1); } ; diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out index bcc743f4851..103a22a3b1d 100644 --- a/src/test/regress/expected/xml.out +++ b/src/test/regress/expected/xml.out @@ -1373,6 +1373,10 @@ EXPLAIN (COSTS OFF, VERBOSE) SELECT * FROM xmltableview1; -- errors SELECT * FROM XMLTABLE (ROW () PASSING null COLUMNS v1 timestamp) AS f (v1, v2); ERROR: XMLTABLE function has 1 columns available but 2 columns specified +SELECT * FROM XMLTABLE (ROW () PASSING null COLUMNS v1 timestamp __pg__is_not_null 1) AS f (v1); +ERROR: option name "__pg__is_not_null" cannot be used in XMLTABLE +LINE 1: ...MLTABLE (ROW () PASSING null COLUMNS v1 timestamp __pg__is_n... + ^ -- XMLNAMESPACES tests SELECT * FROM XMLTABLE(XMLNAMESPACES('http://x.y' AS zz), '/zz:rows/zz:row' diff --git a/src/test/regress/expected/xml_1.out b/src/test/regress/expected/xml_1.out index a1c5d314171..73c411118a3 100644 --- a/src/test/regress/expected/xml_1.out +++ b/src/test/regress/expected/xml_1.out @@ -1047,6 +1047,10 @@ EXPLAIN (COSTS OFF, VERBOSE) SELECT * FROM xmltableview1; -- errors SELECT * FROM XMLTABLE (ROW () PASSING null COLUMNS v1 timestamp) AS f (v1, v2); ERROR: XMLTABLE function has 1 columns available but 2 columns specified +SELECT * FROM XMLTABLE (ROW () PASSING null COLUMNS v1 timestamp __pg__is_not_null 1) AS f (v1); +ERROR: option name "__pg__is_not_null" cannot be used in XMLTABLE +LINE 1: ...MLTABLE (ROW () PASSING null COLUMNS v1 timestamp __pg__is_n... + ^ -- XMLNAMESPACES tests SELECT * FROM XMLTABLE(XMLNAMESPACES('http://x.y' AS zz), '/zz:rows/zz:row' diff --git a/src/test/regress/expected/xml_2.out b/src/test/regress/expected/xml_2.out index 045641dae64..a85d95358d9 100644 --- a/src/test/regress/expected/xml_2.out +++ b/src/test/regress/expected/xml_2.out @@ -1359,6 +1359,10 @@ EXPLAIN (COSTS OFF, VERBOSE) SELECT * FROM xmltableview1; -- errors SELECT * FROM XMLTABLE (ROW () PASSING null COLUMNS v1 timestamp) AS f (v1, v2); ERROR: XMLTABLE function has 1 columns available but 2 columns specified +SELECT * FROM XMLTABLE (ROW () PASSING null COLUMNS v1 timestamp __pg__is_not_null 1) AS f (v1); +ERROR: option name "__pg__is_not_null" cannot be used in XMLTABLE +LINE 1: ...MLTABLE (ROW () PASSING null COLUMNS v1 timestamp __pg__is_n... + ^ -- XMLNAMESPACES tests SELECT * FROM XMLTABLE(XMLNAMESPACES('http://x.y' AS zz), '/zz:rows/zz:row' diff --git a/src/test/regress/sql/xml.sql b/src/test/regress/sql/xml.sql index 4c3520ce898..0ea4f508837 100644 --- a/src/test/regress/sql/xml.sql +++ b/src/test/regress/sql/xml.sql @@ -435,6 +435,8 @@ EXPLAIN (COSTS OFF, VERBOSE) SELECT * FROM xmltableview1; -- errors SELECT * FROM XMLTABLE (ROW () PASSING null COLUMNS v1 timestamp) AS f (v1, v2); +SELECT * FROM XMLTABLE (ROW () PASSING null COLUMNS v1 timestamp __pg__is_not_null 1) AS f (v1); + -- XMLNAMESPACES tests SELECT * FROM XMLTABLE(XMLNAMESPACES('http://x.y' AS zz), '/zz:rows/zz:row' -- 2.43.0