From d0378c8a8c502c7d14b3e4b062988a3f1a0af6ba Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Sat, 23 Nov 2013 20:04:13 -0500 Subject: Fix array slicing of int2vector and oidvector values. The previous coding labeled expressions such as pg_index.indkey[1:3] as being of int2vector type; which is not right because the subscript bounds of such a result don't, in general, satisfy the restrictions of int2vector. To fix, implicitly promote the result of slicing int2vector to int2[], or oidvector to oid[]. This is similar to what we've done with domains over arrays, which is a good analogy because these types are very much like restricted domains of the corresponding regular-array types. A side-effect is that we now also forbid array-element updates on such columns, eg while "update pg_index set indkey[4] = 42" would have worked before if you were superuser (and corrupted your catalogs irretrievably, no doubt) it's now disallowed. This seems like a good thing since, again, some choices of subscripting would've led to results not satisfying the restrictions of int2vector. The case of an array-slice update was rejected before, though with a different error message than you get now. We could make these cases work in future if we added a cast from int2[] to int2vector (with a cast function checking the subscript restrictions) but it seems unlikely that there's any value in that. Per report from Ronan Dunklau. Back-patch to all supported branches because of the crash risks involved. --- src/backend/parser/parse_node.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'src/backend/parser/parse_node.c') diff --git a/src/backend/parser/parse_node.c b/src/backend/parser/parse_node.c index f775850e049..093b789d23f 100644 --- a/src/backend/parser/parse_node.c +++ b/src/backend/parser/parse_node.c @@ -267,6 +267,18 @@ transformArraySubscripts(ParseState *pstate, if (!OidIsValid(elementType)) elementType = transformArrayType(arrayType); + /* + * We treat int2vector and oidvector as though they were domains over + * int2[] and oid[]. This is needed because array slicing could create an + * array that doesn't satisfy the dimensionality constraints of the + * xxxvector type; so we want the result of a slice operation to be + * considered to be of the more general type. + */ + if (arrayType == INT2VECTOROID) + arrayType = INT2ARRAYOID; + else if (arrayType == OIDVECTOROID) + arrayType = OIDARRAYOID; + /* * A list containing only single subscripts refers to a single array * element. If any of the items are double subscripts (lower:upper), then -- cgit v1.2.3