From 9acc1985917e931881e6b71fe2bd337a02f9a934 Mon Sep 17 00:00:00 2001
From: Sean Corfield <sean@corfield.org>
Date: Thu, 20 Aug 2020 11:59:07 -0700
Subject: [PATCH] Treat null ResultSetMetaData as having no columns

---
 CHANGELOG.md                 | 3 +++
 src/next/jdbc/result_set.clj | 8 ++++----
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ac4bbdf..136f197 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,9 @@
 
 Only accretive/fixative changes will be made from now on.
 
+Changes made on **develop** since the 1.1.582 release:
+* If `ResultSet.getMetaData()` returns `null`, we assume the column count is zero, i.e., an empty result set.
+
 ## Stable Builds
 
 * 2020-08-05 -- 1.1.582
diff --git a/src/next/jdbc/result_set.clj b/src/next/jdbc/result_set.clj
index 8c41ae2..84c8969 100644
--- a/src/next/jdbc/result_set.clj
+++ b/src/next/jdbc/result_set.clj
@@ -40,13 +40,13 @@
           (if-let [q (not-empty (.getTableName rsmeta i))]
             (keyword q (.getColumnLabel rsmeta i))
             (keyword (.getColumnLabel rsmeta i))))
-        (range 1 (inc (.getColumnCount rsmeta)))))
+        (range 1 (inc (try (.getColumnCount rsmeta) (catch Throwable _ 0))))))
 
 (defn get-unqualified-column-names
   "Given `ResultSetMetaData`, return a vector of unqualified column names."
   [^ResultSetMetaData rsmeta _]
   (mapv (fn [^Integer i] (keyword (.getColumnLabel rsmeta i)))
-        (range 1 (inc (.getColumnCount rsmeta)))))
+        (range 1 (inc (try (.getColumnCount rsmeta) (catch Throwable _ 0))))))
 
 (defn get-modified-column-names
   "Given `ResultSetMetaData`, return a vector of modified column names, each
@@ -62,7 +62,7 @@
             (if-let [q (some-> (.getTableName rsmeta i) (qf) (not-empty))]
               (keyword q (-> (.getColumnLabel rsmeta i) (lf)))
               (keyword (-> (.getColumnLabel rsmeta i) (lf)))))
-          (range 1 (inc (.getColumnCount rsmeta))))))
+          (range 1 (inc (try (.getColumnCount rsmeta) (catch Throwable _ 0)))))))
 
 (defn get-unqualified-modified-column-names
   "Given `ResultSetMetaData`, return a vector of unqualified modified column
@@ -73,7 +73,7 @@
   (let [lf (:label-fn opts)]
     (assert lf ":label-fn is required")
     (mapv (fn [^Integer i] (keyword (lf (.getColumnLabel rsmeta i))))
-          (range 1 (inc (.getColumnCount rsmeta))))))
+          (range 1 (inc (try (.getColumnCount rsmeta) (catch Throwable _ 0)))))))
 
 (defn- lower-case
   "Converts a string to lower case in the US locale to avoid problems in