From 31bc839724439440b2e94ea616b28ce5be94e19c Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Sun, 23 Dec 2012 14:07:24 -0500 Subject: [PATCH] Prevent failure when RowExpr or XmlExpr is parse-analyzed twice. transformExpr() is required to cope with already-transformed expression trees, for various ugly-but-not-quite-worth-cleaning-up reasons. However, some of its newer subroutines hadn't gotten the memo. This accounts for bug #7763 from Norbert Buchmuller: transformRowExpr() was overwriting the previously determined type of a RowExpr during CREATE TABLE LIKE INCLUDING INDEXES. Additional investigation showed that transformXmlExpr had the same kind of problem, but all the other cases seem to be safe. Andres Freund and Tom Lane --- src/backend/parser/gram.y | 1 + src/backend/parser/parse_expr.c | 19 +++++++++++++++++-- src/include/nodes/primnodes.h | 3 ++- 3 files changed, 20 insertions(+), 3 deletions(-) diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index ad98b364f1..456887665a 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -13341,6 +13341,7 @@ makeXmlExpr(XmlExprOp op, char *name, List *named_args, List *args, x->args = args; /* xmloption, if relevant, must be filled in by caller */ /* type and typmod will be filled in during parse analysis */ + x->type = InvalidOid; /* marks the node as not analyzed */ x->location = location; return (Node *) x; } diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c index e9267c56fc..3b1b6d0139 100644 --- a/src/backend/parser/parse_expr.c +++ b/src/backend/parser/parse_expr.c @@ -92,6 +92,8 @@ static Expr *make_distinct_op(ParseState *pstate, List *opname, * function argument to the required type (via coerce_type()) * can apply transformExpr to an already-transformed subexpression. * An example here is "SELECT count(*) + 1.0 FROM table". + * 3. CREATE TABLE t1 (LIKE t2 INCLUDING INDEXES) can pass in + * already-transformed index expressions. * While it might be possible to eliminate these cases, the path of * least resistance so far has been to ensure that transformExpr() does * no damage if applied to an already-transformed tree. This is pretty @@ -1775,11 +1777,17 @@ transformArrayExpr(ParseState *pstate, A_ArrayExpr *a, static Node * transformRowExpr(ParseState *pstate, RowExpr *r) { - RowExpr *newr = makeNode(RowExpr); + RowExpr *newr; char fname[16]; int fnum; ListCell *lc; + /* If we already transformed this node, do nothing */ + if (OidIsValid(r->row_typeid)) + return (Node *) r; + + newr = makeNode(RowExpr); + /* Transform the field expressions */ newr->args = transformExpressionList(pstate, r->args, pstate->p_expr_kind); @@ -1880,16 +1888,23 @@ transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m) static Node * transformXmlExpr(ParseState *pstate, XmlExpr *x) { - XmlExpr *newx = makeNode(XmlExpr); + XmlExpr *newx; ListCell *lc; int i; + /* If we already transformed this node, do nothing */ + if (OidIsValid(x->type)) + return (Node *) x; + + newx = makeNode(XmlExpr); newx->op = x->op; if (x->name) newx->name = map_sql_identifier_to_xml_name(x->name, false, false); else newx->name = NULL; newx->xmloption = x->xmloption; + newx->type = XMLOID; /* this just marks the node as transformed */ + newx->typmod = -1; newx->location = x->location; /* diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h index a233fce003..5eb5f8b4cd 100644 --- a/src/include/nodes/primnodes.h +++ b/src/include/nodes/primnodes.h @@ -958,7 +958,8 @@ typedef struct MinMaxExpr * * Note: result type/typmod/collation are not stored, but can be deduced * from the XmlExprOp. The type/typmod fields are just used for display - * purposes, and are NOT the true result type of the node. + * purposes, and are NOT necessarily the true result type of the node. + * (We also use type == InvalidOid to mark a not-yet-parse-analyzed XmlExpr.) */ typedef enum XmlExprOp { -- 2.40.0