From 208b018f6b807f76053e195cf8fbfc1f2f67f7b4 Mon Sep 17 00:00:00 2001
From: itsumura-h <39766805+itsumura-h@users.noreply.github.com>
Date: Thu, 5 Dec 2019 18:28:47 +0900
Subject: [PATCH] fix db_mysql getRow() when column is null error raised
 (#12806) [backport]

* fix db_mysql getRow()
* added if y == nil [backport]
---
 lib/system.nim | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/lib/system.nim b/lib/system.nim
index 2c5790d5ee..cb211e6a9d 100644
--- a/lib/system.nim
+++ b/lib/system.nim
@@ -3412,9 +3412,10 @@ elif hasAlloc:
   {.push stack_trace:off, profiler:off.}
   proc add*(x: var string, y: cstring) =
     var i = 0
-    while y[i] != '\0':
-      add(x, y[i])
-      inc(i)
+    if y != nil:
+      while y[i] != '\0':
+        add(x, y[i])
+        inc(i)
   {.pop.}
 
 when defined(nimvarargstyped):