package/avro-c: fix build without C++

Fixes:
 - http://autobuild.buildroot.org/results/135e246aa70f28c6b9aea5fd6b0eb9c7b45ebfe7

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/avro-c/0002-CMakeLists.txt-fix-build-without-C.patch

@@ -0,0 +1,92 @@
+From cdab7db8ad81884cfb21cc1cf94c981c59d17ef4 Mon Sep 17 00:00:00 2001
+From: Fabrice Fontaine <fontaine.fabrice@gmail.com>
+Date: Mon, 30 Dec 2019 12:32:20 +0100
+Subject: [PATCH] CMakeLists.txt: fix build without C++
+
+Specify that AvroC is a C project and remove tests_cpp.cpp to avoid the
+following build failure if a C++ compiler is not found:
+
+CMake Error at CMakeLists.txt:20 (project):
+  The CMAKE_CXX_COMPILER:
+
+    /home/naourr/work/instance-2/output-1/host/bin/microblazeel-buildroot-linux-uclibc-g++
+
+  is not a full path to an existing compiler tool.
+
+  Tell CMake where to find the compiler by setting either the environment
+  variable "CXX" or the CMake cache entry CMAKE_CXX_COMPILER to the full path
+  to the compiler, or to the compiler name if it is in the PATH.
+
+Fixes:
+ - http://autobuild.buildroot.org/results/135e246aa70f28c6b9aea5fd6b0eb9c7b45ebfe7
+
+Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
+[Upstream status: https://github.com/apache/avro/pull/754]
+---
+ CMakeLists.txt       |  2 +-
+ tests/CMakeLists.txt |  1 -
+ tests/test_cpp.cpp   | 27 ---------------------------
+ 3 files changed, 1 insertion(+), 29 deletions(-)
+ delete mode 100644 lang/c/tests/test_cpp.cpp
+
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 11cbf018..b75418c3 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -17,7 +17,7 @@
+ # under the License.
+ #
+ cmake_minimum_required(VERSION 2.4)
+-project(AvroC)
++project(AvroC C)
+ enable_testing()
+ 
+ set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${CMAKE_SOURCE_DIR})
+diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
+index b9e8fe1d..2e84a06a 100644
+--- a/tests/CMakeLists.txt
++++ b/tests/CMakeLists.txt
+@@ -81,7 +81,6 @@ add_avro_test_checkmem(test_avro_1405)
+ add_avro_test_checkmem(test_avro_1572)
+ add_avro_test(test_avro_data) # Skip memory check for datum. Deprecated and has a lot of memory issues
+ add_avro_test_checkmem(test_refcount)
+-add_avro_test_checkmem(test_cpp test_cpp.cpp)
+ add_avro_test_checkmem(test_avro_1379)
+ add_avro_test_checkmem(test_avro_1691)
+ add_avro_test_checkmem(test_avro_1906)
+diff --git a/lang/c/tests/test_cpp.cpp b/lang/c/tests/test_cpp.cpp
+deleted file mode 100644
+index 13f98a9b..00000000
+--- a/tests/test_cpp.cpp
++++ /dev/null
+@@ -1,27 +0,0 @@
+-/*
+- * Licensed to the Apache Software Foundation (ASF) under one or more
+- * contributor license agreements.  See the NOTICE file distributed with
+- * this work for additional information regarding copyright ownership.
+- * The ASF licenses this file to you under the Apache License, Version 2.0
+- * (the "License"); you may not use this file except in compliance with
+- * the License.  You may obtain a copy of the License at
+- *
+- * https://www.apache.org/licenses/LICENSE-2.0
+- *
+- * Unless required by applicable law or agreed to in writing, software
+- * distributed under the License is distributed on an "AS IS" BASIS,
+- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+- * implied.  See the License for the specific language governing
+- * permissions and limitations under the License.
+- */
+-
+-#include "avro.h"
+-
+-int main(int argc, char **argv)
+-{
+-    (void)argc;
+-    (void)argv;
+-
+-	return 0;
+-}
+-
+-- 
+2.24.0
+