[PATCH] Fix static build in combination with static openssl library

[Ton van den Heuvel <tonvandenheuvel@xxxxxxxxx>]

Building libssh statically using a static openssl library fails
because of failing configure checks.

From d98ec360323f1a614bc9c43a09bd71af18620075 Mon Sep 17 00:00:00 2001
From: Ton van den Heuvel <ton@xxxxxxxxxxxxxx>
Date: Thu, 11 May 2017 13:21:04 +0200
Subject: [PATCH] Fix static libssh build

Fix static libssh build in combination with a static openssl library.
---
 ConfigureChecks.cmake | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/ConfigureChecks.cmake b/ConfigureChecks.cmake
index f56458070..2f755b79e 100644
--- a/ConfigureChecks.cmake
+++ b/ConfigureChecks.cmake
@@ -101,22 +101,37 @@ if (OPENSSL_FOUND)
 
     set(CMAKE_REQUIRED_INCLUDES ${OPENSSL_INCLUDE_DIR})
     set(CMAKE_REQUIRED_LIBRARIES ${OPENSSL_CRYPTO_LIBRARY})
+    if (OPENSSL_USE_STATIC_LIBS)
+        set(CMAKE_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES} dl)
+    endif()
     check_function_exists(EVP_aes_128_ctr HAVE_OPENSSL_EVP_AES_CTR)
 
     set(CMAKE_REQUIRED_INCLUDES ${OPENSSL_INCLUDE_DIR})
     set(CMAKE_REQUIRED_LIBRARIES ${OPENSSL_CRYPTO_LIBRARY})
+    if (OPENSSL_USE_STATIC_LIBS)
+        set(CMAKE_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES} dl)
+    endif()
     check_function_exists(EVP_aes_128_cbc HAVE_OPENSSL_EVP_AES_CBC)
 
     set(CMAKE_REQUIRED_INCLUDES ${OPENSSL_INCLUDE_DIR})
     set(CMAKE_REQUIRED_LIBRARIES ${OPENSSL_CRYPTO_LIBRARY})
+    if (OPENSSL_USE_STATIC_LIBS)
+        set(CMAKE_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES} dl)
+    endif()
     check_function_exists(CRYPTO_THREADID_set_callback HAVE_OPENSSL_CRYPTO_THREADID_SET_CALLBACK)
 
     set(CMAKE_REQUIRED_INCLUDES ${OPENSSL_INCLUDE_DIR})
     set(CMAKE_REQUIRED_LIBRARIES ${OPENSSL_CRYPTO_LIBRARY})
+    if (OPENSSL_USE_STATIC_LIBS)
+        set(CMAKE_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES} dl)
+    endif()
     check_function_exists(CRYPTO_ctr128_encrypt HAVE_OPENSSL_CRYPTO_CTR128_ENCRYPT)
 
     set(CMAKE_REQUIRED_INCLUDES ${OPENSSL_INCLUDE_DIR})
     set(CMAKE_REQUIRED_LIBRARIES ${OPENSSL_CRYPTO_LIBRARY})
+    if (OPENSSL_USE_STATIC_LIBS)
+        set(CMAKE_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES} dl)
+    endif()
     check_function_exists(EVP_CIPHER_CTX_new HAVE_OPENSSL_EVP_CIPHER_CTX_NEW)
 endif()
 
-- 
2.13.2