diff options
| author | Tom Lane | 2022-05-09 18:15:37 +0000 |
|---|---|---|
| committer | Tom Lane | 2022-05-09 18:15:37 +0000 |
| commit | 4eabaffcada25206c3f8f89f7cb0b27ffb9372bc (patch) | |
| tree | 6e743287106d29f782bb092e9436cc8c3c7ca68a | |
| parent | 86a21803c7d860bd0cbd8c81c34cc9250d4cc173 (diff) | |
Fix core dump in transformValuesClause when there are no columns.
The parser code that transformed VALUES from row-oriented to
column-oriented lists failed if there were zero columns.
You can't write that straightforwardly (though probably you
should be able to), but the case can be reached by expanding
a "tab.*" reference to a zero-column table.
Per bug #17477 from Wang Ke. Back-patch to all supported branches.
Discussion: https://postgr.es/m/17477-0af3c6ac6b0a6ae0@postgresql.org
| -rw-r--r-- | src/backend/parser/analyze.c | 21 | ||||
| -rw-r--r-- | src/test/regress/expected/select.out | 7 | ||||
| -rw-r--r-- | src/test/regress/sql/select.sql | 5 |
3 files changed, 19 insertions, 14 deletions
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c index 3678dcfc9da..14be0882578 100644 --- a/src/backend/parser/analyze.c +++ b/src/backend/parser/analyze.c @@ -1346,7 +1346,7 @@ static Query * transformValuesClause(ParseState *pstate, SelectStmt *stmt) { Query *qry = makeNode(Query); - List *exprsLists; + List *exprsLists = NIL; List *coltypes = NIL; List *coltypmods = NIL; List *colcollations = NIL; @@ -1431,6 +1431,9 @@ transformValuesClause(ParseState *pstate, SelectStmt *stmt) /* Release sub-list's cells to save memory */ list_free(sublist); + + /* Prepare an exprsLists element for this row */ + exprsLists = lappend(exprsLists, NIL); } /* @@ -1485,25 +1488,15 @@ transformValuesClause(ParseState *pstate, SelectStmt *stmt) /* * Finally, rearrange the coerced expressions into row-organized lists. */ - exprsLists = NIL; - foreach(lc, colexprs[0]) - { - Node *col = (Node *) lfirst(lc); - List *sublist; - - sublist = list_make1(col); - exprsLists = lappend(exprsLists, sublist); - } - list_free(colexprs[0]); - for (i = 1; i < sublist_length; i++) + for (i = 0; i < sublist_length; i++) { forboth(lc, colexprs[i], lc2, exprsLists) { Node *col = (Node *) lfirst(lc); List *sublist = lfirst(lc2); - /* sublist pointer in exprsLists won't need adjustment */ - (void) lappend(sublist, col); + sublist = lappend(sublist, col); + lfirst(lc2) = sublist; } list_free(colexprs[i]); } diff --git a/src/test/regress/expected/select.out b/src/test/regress/expected/select.out index 1fab5136d29..0df53f0f619 100644 --- a/src/test/regress/expected/select.out +++ b/src/test/regress/expected/select.out @@ -517,6 +517,13 @@ TABLE int8_tbl; 4567890123456789 | -4567890123456789 (9 rows) +-- corner case: VALUES with no columns +CREATE TEMP TABLE nocols(); +INSERT INTO nocols DEFAULT VALUES; +SELECT * FROM nocols n, LATERAL (VALUES(n.*)) v; +-- +(1 row) + -- -- Test ORDER BY options -- diff --git a/src/test/regress/sql/select.sql b/src/test/regress/sql/select.sql index c80429e7d03..3f8cecc3f3b 100644 --- a/src/test/regress/sql/select.sql +++ b/src/test/regress/sql/select.sql @@ -148,6 +148,11 @@ SELECT 2+2, 57 UNION ALL TABLE int8_tbl; +-- corner case: VALUES with no columns +CREATE TEMP TABLE nocols(); +INSERT INTO nocols DEFAULT VALUES; +SELECT * FROM nocols n, LATERAL (VALUES(n.*)) v; + -- -- Test ORDER BY options -- |