BUG #11457: The below query crashes 9.3.5, but not 9.3.4

The following bug has been logged on the website:

Bug reference:      11457
Logged by:          Nelson Page
Email address:      npage@dynamicsignal.com
PostgreSQL version: 9.3.5
Operating system:   WIndows 8.1
Description:

SELECT

    "GroupBy1"."A1" AS "C1"

    FROM ( SELECT Count(1) AS "A1"

        FROM   (SELECT

            "UnionAll4"."C1"

            FROM  (SELECT

                "UnionAll3"."C1"

                FROM  (SELECT

                    "UnionAll2"."C1"

                    FROM  (SELECT

                        "UnionAll1"."activityId" AS "C1"

                        FROM  (SELECT

                            "Extent1"."activityId"

                            FROM "ActivityBlogCampaign" AS "Extent1"

                        UNION ALL

                            SELECT

                            "Extent2"."activityId"

                            FROM "ActivitySubmitArticle" AS "Extent2") AS "UnionAll1"

                    UNION ALL

                        SELECT

                        "Extent3"."activityId"

                        FROM "ActivityCuratedPost" AS "Extent3") AS "UnionAll2"

                UNION ALL

                    SELECT

                    "Extent4"."activityId"

                    FROM "ActivitySurvey" AS "Extent4") AS "UnionAll3"

            UNION ALL

                SELECT

                "Extent5"."activityId"

                FROM "ActivityHashTag" AS "Extent5") AS "UnionAll4"

        UNION ALL

            SELECT

            "Extent6"."activityId"

            FROM "ActivityShareArticle" AS "Extent6") AS "UnionAll5"

        INNER JOIN "Activity" AS "Extent7" ON "UnionAll5"."C1" =
"Extent7"."activityId"
        GROUP BY "Extent7"."activityId"

    ) As "GroupBy1"