From 70dafcf5da29ff772ca6d4dcdd24d5548a0ddd31 Mon Sep 17 00:00:00 2001
From: sfan5 <sfan5@live.de>
Date: Wed, 1 Sep 2021 10:37:38 +0200
Subject: Check for required libzstd APIs in cmake

It's very unlikely that anyone uses a zstd version this old, but if they do fail early.
---
 cmake/Modules/FindZstd.cmake | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/cmake/Modules/FindZstd.cmake b/cmake/Modules/FindZstd.cmake
index 461e4d5a6..e28e1334b 100644
--- a/cmake/Modules/FindZstd.cmake
+++ b/cmake/Modules/FindZstd.cmake
@@ -4,6 +4,22 @@ find_path(ZSTD_INCLUDE_DIR NAMES zstd.h)
 
 find_library(ZSTD_LIBRARY NAMES zstd)
 
+if(ZSTD_INCLUDE_DIR AND ZSTD_LIBRARY)
+	# Check that the API we use exists
+	include(CheckSymbolExists)
+	unset(HAVE_ZSTD_INITCSTREAM CACHE)
+	set(CMAKE_REQUIRED_INCLUDES ${ZSTD_INCLUDE_DIR})
+	set(CMAKE_REQUIRED_LIBRARIES ${ZSTD_LIBRARY})
+	check_symbol_exists(ZSTD_initCStream zstd.h HAVE_ZSTD_INITCSTREAM)
+	unset(CMAKE_REQUIRED_INCLUDES)
+	unset(CMAKE_REQUIRED_LIBRARIES)
+
+	if(NOT HAVE_ZSTD_INITCSTREAM)
+		unset(ZSTD_INCLUDE_DIR CACHE)
+		unset(ZSTD_LIBRARY CACHE)
+	endif()
+endif()
+
 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args(Zstd DEFAULT_MSG ZSTD_LIBRARY ZSTD_INCLUDE_DIR)
 
-- 
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