Fix Curl Linking

CMake/Dependencies/libcurl-CMakeLists.txt

@@ -31,10 +31,13 @@ if (WIN32)
     set(CMAKE_ARGS ${CMAKE_ARGS} -DCMAKE_USE_WINSSL=1 -DCURL_STATIC_CRT=1)
 endif()
 
+SET(PATCH_COMMAND git apply --verbose --ignore-whitespace ${CMAKE_CURRENT_LIST_DIR}/libcurl-cmake-config.patch)
+
 ExternalProject_Add(project_libcurl
     GIT_REPOSITORY    https://github.com/curl/curl.git
     GIT_TAG           curl-7_68_0
     PREFIX            ${CMAKE_CURRENT_BINARY_DIR}/build
     CMAKE_ARGS        ${CMAKE_ARGS}
+    PATCH_COMMAND     ${PATCH_COMMAND}
     BUILD_ALWAYS      TRUE
     TEST_COMMAND      "")

CMake/Dependencies/libcurl-cmake-config.patch

@@ -0,0 +1,13 @@
+diff --git a/CMake/curl-config.cmake.in b/CMake/curl-config.cmake.in
+index 1294e173a..99c1e535f 100644
+--- a/CMake/curl-config.cmake.in
++++ b/CMake/curl-config.cmake.in
+@@ -10,3 +10,7 @@ endif()
+
+ include("${CMAKE_CURRENT_LIST_DIR}/@TARGETS_EXPORT_NAME@.cmake")
+ check_required_components("@PROJECT_NAME@")
++
++# For compatibility with CMake's FindCURL.cmake
++set(CURL_LIBRARIES @PROJECT_NAME@::libcurl)
++set_and_check(CURL_INCLUDE_DIR ${OPEN_SRC_INSTALL_PREFIX}/include)
+\ No newline at end of file

CMake/Utilities.cmake

@@ -76,6 +76,13 @@ function(build_dependency lib_name)
   configure_file(
     ./CMake/Dependencies/lib${lib_name}-CMakeLists.txt
     ${OPEN_SRC_INSTALL_PREFIX}/lib${lib_name}/CMakeLists.txt COPYONLY)
+
+  # when OPEN_SRC_INSTALL_PREFIX has non-default value, patch files must be copied to temporary location,
+  # otherwise build fails as it couldn't refer to the caller's CMake process directory.
+  file(GLOB LIB_PATCHES "./CMake/Dependencies/lib${lib_name}-*.patch")
+  message(STATUS "Copying patches for dependency ${lib_name}: ${LIB_PATCHES}")
+  file(COPY ${LIB_PATCHES} DESTINATION ${OPEN_SRC_INSTALL_PREFIX}/lib${lib_name}/)
+
   execute_process(
     COMMAND ${CMAKE_COMMAND} ${build_args}
             -DOPEN_SRC_INSTALL_PREFIX=${OPEN_SRC_INSTALL_PREFIX} -G

CMakeLists.txt

@@ -168,15 +168,19 @@ else()
 endif()
 
 if(BUILD_COMMON_CURL)
-  if (WIN32)
+  if (OPEN_SRC_INSTALL_PREFIX)
+    set(CMAKE_PREFIX_PATH "${OPEN_SRC_INSTALL_PREFIX}/lib/cmake/curl" ${CMAKE_PREFIX_PATH})
+    find_package(CURL REQUIRED PATHS ${OPEN_SRC_INSTALL_PREFIX})
+  else()
     find_package(CURL REQUIRED)
+  endif()
+  if (WIN32)
     set(CURL_LIBRARIES CURL::libcurl)
   else()
-    pkg_check_modules(CURL REQUIRED libcurl)
+    set(CURL_LIBRARIES curl)
+    set(OPEN_SRC_INCLUDE_DIRS ${OPEN_SRC_INCLUDE_DIRS} ${CURL_INCLUDE_DIR})
   endif()
 
-  set(OPEN_SRC_INCLUDE_DIRS ${OPEN_SRC_INCLUDE_DIRS} ${CURL_INCLUDE_DIRS})
-  link_directories(${CURL_LIBRARY_DIRS})
 endif()
 
 if (BUILD_COMMON_LWS)