A fix and test case for the bug reported by Reggie: if character set

of client equals to character set of connection, possibly required
conversion to character set of column is not performed
(prepared statements, data is supplied using placeholders).

sql/item.cc

@@ -1218,6 +1218,10 @@ bool Item_param::convert_str_value(THD *thd)
                               value.cs_info.character_set_client,
                               value.cs_info.final_character_set_of_str_value);
     }
+    else
+      str_value.set_charset(value.cs_info.final_character_set_of_str_value);
+    /* Here str_value is guaranteed to be in final_character_set_of_str_value */
+
     max_length= str_value.length();
     decimals= 0;
     /*

tests/client_test.c

@@ -11152,6 +11152,73 @@ static void test_bug4172()
 }
 
 
+static void test_conversion()
+{
+  MYSQL_STMT *stmt;
+  const char *stmt_text;
+  int rc;
+  MYSQL_BIND bind[1];
+  char buff[4];
+  ulong length;
+
+  myheader("test_conversion");
+
+  stmt_text= "DROP TABLE IF EXISTS t1";
+  rc= mysql_real_query(mysql, stmt_text, strlen(stmt_text));
+  myquery(rc);
+  stmt_text= "CREATE TABLE t1 (a TEXT) DEFAULT CHARSET latin1";
+  rc= mysql_real_query(mysql, stmt_text, strlen(stmt_text));
+  myquery(rc);
+  stmt_text= "SET character_set_connection=utf8, character_set_client=utf8, "
+             " character_set_results=latin1";
+  rc= mysql_real_query(mysql, stmt_text, strlen(stmt_text));
+  myquery(rc);
+
+  stmt= mysql_stmt_init(mysql);
+
+  stmt_text= "INSERT INTO t1 (a) VALUES (?)";
+  rc= mysql_stmt_prepare(stmt, stmt_text, strlen(stmt_text));
+  check_execute(stmt, rc);
+
+  bzero(bind, sizeof(bind));
+  bind[0].buffer= buff;
+  bind[0].length= &length;
+  bind[0].buffer_type= MYSQL_TYPE_STRING;
+
+  mysql_stmt_bind_param(stmt, bind);
+
+  buff[0]= 0xC3;
+  buff[1]= 0xA0;
+  length= 2;
+
+  rc= mysql_stmt_execute(stmt);
+  check_execute(stmt, rc);
+
+  stmt_text= "SELECT a FROM t1";
+  rc= mysql_stmt_prepare(stmt, stmt_text, strlen(stmt_text));
+  check_execute(stmt, rc);
+  rc= mysql_stmt_execute(stmt);
+  check_execute(stmt, rc);
+
+  bind[0].buffer_length= sizeof(buff);
+  mysql_stmt_bind_result(stmt, bind);
+
+  rc= mysql_stmt_fetch(stmt);
+  DIE_UNLESS(rc == 0);
+  DIE_UNLESS(length == 1);
+  DIE_UNLESS((uchar) buff[0] == 0xE0);
+  rc= mysql_stmt_fetch(stmt);
+  DIE_UNLESS(rc == MYSQL_NO_DATA);
+
+  mysql_stmt_close(stmt);
+  stmt_text= "DROP TABLE t1";
+  rc= mysql_real_query(mysql, stmt_text, strlen(stmt_text));
+  myquery(rc);
+  stmt_text= "SET NAMES DEFAULT";
+  rc= mysql_real_query(mysql, stmt_text, strlen(stmt_text));
+  myquery(rc);
+}
+
 
 /*
   Read and parse arguments and MySQL options from my.cnf
@@ -11471,6 +11538,10 @@ int main(int argc, char **argv)
     test_bug6096();         /* max_length for numeric columns */
     test_bug4172();         /* floating point conversions in libmysql */
 
+    test_conversion();      /* placeholder value is not converted to
+                               character set of column if character set
+                               of connection equals to character set of
+                               client */
     /*
       XXX: PLEASE RUN THIS PROGRAM UNDER VALGRIND AND VERIFY THAT YOUR TEST
       DOESN'T CONTAIN WARNINGS/ERRORS BEFORE YOU PUSH.