fix db_mysql getRow() when column is null error raised (#12806) [backport]

* fix db_mysql getRow() * added if y == nil [backport]
2019-12-05 18:28:47 +09:00 · 2019-12-05 18:28:47 +09:00 · 208b018f6b
commit 208b018f6b
parent 0987872675
1 changed files with 4 additions and 3 deletions
--- 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):