MDEV-8407 Numeric errors, server crash with COLUMN_JSON() on DECIMAL with precision > 40

In fact it was error in decimal library (incorrect processing of buffer overflow) invisible from other server parts because of buffer allocation and precision tests.

1 files changed, 2 insertions, 1 deletions

diff --git a/strings/decimal.c b/strings/decimal.c
index 07ccc537e47..8dbe1bd57f4 100644
--- a/strings/decimal.c
+++ b/strings/decimal.c
@@ -383,7 +383,8 @@ int decimal2string(const decimal_t *from, char *to, int *to_len,
     }
     else
       frac-=j;
-    len= from->sign + intg_len + test(frac) + frac_len;
+    frac_len= frac;
+    len= from->sign + intg_len + test(frac) + frac;
   }
   *to_len=len;
   s[len]=0;