(PDB-5161) engine/parse-dot-query: fix text[] syntax/quoting

Add jdbc/strs->db-array that creates a proper postgres text[] array
literal, including backslash escaping every string element, and use us
it in parse-dot-query.  The previous code was treating the elements as
single quoted SQL strings, which doesn't appear to be what postgres
expects.

Author: rbrw

src/puppetlabs/puppetdb/jdbc.clj

@@ -13,7 +13,8 @@
   (:import
    (com.zaxxer.hikari HikariDataSource HikariConfig)
    (java.sql Connection SQLException SQLTransientConnectionException)
-   (java.util.concurrent TimeUnit)))
+   (java.util.concurrent TimeUnit)
+   (org.postgresql.util PGobject)))
 
 (def ^:dynamic *db* nil)
 
@@ -392,6 +393,26 @@
   [s]
   (str "\"" (escape-double-quotes s) "\""))
 
+(defn string->text-array-literal
+  "Escape string s for inclusion in a postgres text[] literal,
+  e.g. \"foo\\\"bar\" becomes the \"foo\\\\\\\"bar\" in
+  '{\"foo\\\\\\\"bar\"}'"
+  ;; https://www.postgresql.org/docs/11/arrays.html#ARRAYS-INPUT
+  ;; https://www.postgresql.org/docs/11/sql-syntax-lexical.html#SQL-SYNTAX-CONSTANTS
+  [s]
+  (assert (string? s))
+  (str \" (str/replace s "\\" "\\\\") \"))
+
+(defn strs->db-array
+  [strs]
+  (assert (every? string? strs))
+  ;; https://www.postgresql.org/docs/11/arrays.html#ARRAYS-INPUT
+  (let [quoted (map string->text-array-literal strs)]
+    (doto (PGobject.)
+      (.setType "text[]")
+      (.setValue (str \{ (str/join \, quoted) \})))))
+
+;; Q: move/replace?
 (defn create-json-path-extraction
   "Given a base json field and a path of keys to traverse, construct the proper
   SQL query of the form base->'key'->'key2'..."

src/puppetlabs/puppetdb/query_eng/engine.clj

@@ -1649,9 +1649,7 @@
       ;; plain integer path components.
       {:node (assoc node :value ["?" "?"] :field column :array-in-path true)
        ;; https://www.postgresql.org/docs/11/arrays.html#ARRAYS-INPUT
-       :state (reduce conj state [(doto (PGobject.)
-                                    (.setType "text[]")
-                                    (.setValue (str "{" (string/join "," (map #(string/replace % "'" "''") path)) "}")))
+       :state (reduce conj state [(jdbc/strs->db-array path)
                                   (su/munge-jsonb-for-storage value)])}
       {:node (assoc node :value "?" :field column :array-in-path false)
        :state (conj state (su/munge-jsonb-for-storage