From 6edc091e7e034b6ba3a764f30391de827179c96a Mon Sep 17 00:00:00 2001
From: rusher <diego.dupin@gmail.com>
Date: Mon, 8 Jun 2020 17:20:38 +0200
Subject: [PATCH] [CONJ-797] autodetection connection collation set to utf8mb4
 equivalent collation for server configured to use UTF8mb3 collation

---
 .../protocol/AbstractConnectProtocol.java      | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/src/main/java/org/mariadb/jdbc/internal/protocol/AbstractConnectProtocol.java b/src/main/java/org/mariadb/jdbc/internal/protocol/AbstractConnectProtocol.java
index e68d33b3c..6e9a5f26e 100644
--- a/src/main/java/org/mariadb/jdbc/internal/protocol/AbstractConnectProtocol.java
+++ b/src/main/java/org/mariadb/jdbc/internal/protocol/AbstractConnectProtocol.java
@@ -1200,10 +1200,28 @@ private byte decideLanguage(int serverLanguage) {
         || (serverLanguage >= 224 && serverLanguage <= 247)) {
       return (byte) serverLanguage;
     }
+
     if (getMajorServerVersion() == 5 && getMinorServerVersion() <= 1) {
       // 5.1 version doesn't know 4 bytes utf8
       return (byte) 33; // utf8_general_ci
     }
+
+    // if server language is utf8mb3, use utf8mb4 equivalent collation
+    if (serverLanguage == 33) {
+      // utf8mb4_general_ci
+      return 45;
+    }
+
+    if (serverLanguage == 83) {
+      // utf8mb4_bin
+      return 46;
+    }
+
+    if (serverLanguage >= 192 && serverLanguage <= 215) {
+      // equivalent utf8mb4 collation
+      return (byte) (serverLanguage - 32);
+    }
+
     return (byte) 224; // UTF8MB4_UNICODE_CI;
   }