cmake: Add an option to disable libidn2

New option USE_LIBIDN2 defaults to ON for libidn2 detection. Prior to
this change libidn2 detection could not be turned off in cmake builds.

Reported-by: William A Rowe Jr
Fixes https://github.com/curl/curl/issues/6361
Closes https://github.com/curl/curl/pull/6362

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7c26e2dcf4596c1b8780bce1cff47c1686871cc3..58f4bfb7c755672c27d956a998019659b4f6396c 100644 (file)
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -618,7 +618,11 @@ if(NOT CURL_DISABLE_LDAPS)
 endif()
 
 # Check for idn
-check_library_exists_concat("idn2" idn2_lookup_ul HAVE_LIBIDN2)
+option(USE_LIBIDN2 "Use libidn2 for IDN support" ON)
+set(HAVE_LIBIDN2 OFF)
+if(USE_LIBIDN2)
+  check_library_exists_concat("idn2" idn2_lookup_ul HAVE_LIBIDN2)
+endif()
 
 # Check for symbol dlopen (same as HAVE_LIBDL)
 check_library_exists("${CURL_LIBS}" dlopen "" HAVE_DLOPEN)