From 537c750e328cd080365e465acd4f0383bf0febf3 Mon Sep 17 00:00:00 2001
From: Oleksandr Byelkin <sanja@mariadb.com>
Date: Thu, 10 Dec 2015 16:17:20 +0100
Subject: MDEV-8521 Drastic loss of precision in COLUMN_JSON() on DOUBLEs

fixed conversion
---
 mysys/ma_dyncol.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

(limited to 'mysys')

diff --git a/mysys/ma_dyncol.c b/mysys/ma_dyncol.c
index 7dfaf29a1a7..06820a0c3c5 100644
--- a/mysys/ma_dyncol.c
+++ b/mysys/ma_dyncol.c
@@ -3837,7 +3837,9 @@ mariadb_dyncol_val_str(DYNAMIC_STRING *str, DYNAMIC_COLUMN_VALUE *val,
         return ER_DYNCOL_RESOURCE;
       break;
     case DYN_COL_DOUBLE:
-      len= my_snprintf(buff, sizeof(buff), "%g", val->x.double_value);
+
+      len= my_gcvt(val->x.double_value, MY_GCVT_ARG_DOUBLE,
+                   sizeof(buff) - 1, buff, NULL);
       if (dynstr_realloc(str, len + (quote ? 2 : 0)))
         return ER_DYNCOL_RESOURCE;
       dynstr_append_mem(str, buff, len);
-- 
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