From 285c66c71ba8ad8633b73a7a9eefc88dad628325 Mon Sep 17 00:00:00 2001
From: Debian Qt/KDE Maintainers <debian-qt-kde@lists.debian.org>
Date: Sat, 17 Dec 2022 15:20:05 +0000
Subject: [PATCH] treat the MYSQL_FIELD as read-only

Origin: upstream, https://code.qt.io/cgit/qt/qtbase.git/commit/?id=549ee216fd5bf2b3
Last-Update: 2021-11-13

The MariaDB-connector-c version 3.2 and MariaDB server version 10.6
cooperate to avoid re-transferring the query metadata, so the fact that
we were modifying it was causing it to improperly decode the DATETIME
data types into string, as we had asked. We ended up with a 7-byte
string that was actually the date binary-encoded.

Gbp-Pq: Name mysql_field_readonly.diff
---
 src/plugins/sqldrivers/mysql/qsql_mysql.cpp | 28 ++++++++++-----------
 1 file changed, 13 insertions(+), 15 deletions(-)

diff --git a/src/plugins/sqldrivers/mysql/qsql_mysql.cpp b/src/plugins/sqldrivers/mysql/qsql_mysql.cpp
index 7ca055eea..49a6ae5b7 100644
--- a/src/plugins/sqldrivers/mysql/qsql_mysql.cpp
+++ b/src/plugins/sqldrivers/mysql/qsql_mysql.cpp
@@ -223,7 +223,7 @@ public:
     struct QMyField
     {
         char *outField = nullptr;
-        MYSQL_FIELD *myField = nullptr;
+        const MYSQL_FIELD *myField = nullptr;
         QMetaType::Type type = QMetaType::UnknownType;
         my_bool nullIndicator = false;
         ulong bufLength = 0ul;
@@ -361,11 +361,10 @@ static bool qIsInteger(int t)
 void QMYSQLResultPrivate::bindBlobs()
 {
     int i;
-    MYSQL_FIELD *fieldInfo;
     MYSQL_BIND *bind;
 
     for(i = 0; i < fields.count(); ++i) {
-        fieldInfo = fields.at(i).myField;
+        const MYSQL_FIELD *fieldInfo = fields.at(i).myField;
         if (qIsBlob(inBinds[i].buffer_type) && meta && fieldInfo) {
             bind = &inBinds[i];
             bind->buffer_length = fieldInfo->max_length;
@@ -392,35 +391,34 @@ bool QMYSQLResultPrivate::bindInValues()
     inBinds = new MYSQL_BIND[fields.size()];
     memset(inBinds, 0, fields.size() * sizeof(MYSQL_BIND));
 
-    MYSQL_FIELD *fieldInfo;
+    const MYSQL_FIELD *fieldInfo;
 
     while((fieldInfo = mysql_fetch_field(meta))) {
+        MYSQL_BIND *bind = &inBinds[i];
+
         QMyField &f = fields[i];
         f.myField = fieldInfo;
-
+        bind->buffer_length = f.bufLength = fieldInfo->length + 1;
+        bind->buffer_type = fieldInfo->type;
         f.type = qDecodeMYSQLType(fieldInfo->type, fieldInfo->flags);
         if (qIsBlob(fieldInfo->type)) {
             // the size of a blob-field is available as soon as we call
             // mysql_stmt_store_result()
             // after mysql_stmt_exec() in QMYSQLResult::exec()
-            fieldInfo->length = 0;
+            bind->buffer_length = f.bufLength = 0;
             hasBlobs = true;
         } else if (qIsInteger(f.type)) {
-            fieldInfo->length = 8;
+            bind->buffer_length = f.bufLength = 8;
         } else {
-            fieldInfo->type = MYSQL_TYPE_STRING;
+            bind->buffer_type = MYSQL_TYPE_STRING;
         }
-        bind = &inBinds[i];
-        field = new char[fieldInfo->length + 1];
-        memset(field, 0, fieldInfo->length + 1);
 
-        bind->buffer_type = fieldInfo->type;
-        bind->buffer = field;
-        bind->buffer_length = f.bufLength = fieldInfo->length + 1;
         bind->is_null = &f.nullIndicator;
         bind->length = &f.bufLength;
         bind->is_unsigned = fieldInfo->flags & UNSIGNED_FLAG ? 1 : 0;
-        f.outField=field;
+
+        char *field = new char[bind->buffer_length + 1]{};
+        bind->buffer = f.outField = field;
 
         ++i;
     }
-- 
2.30.2