runtests: fix `LD_PRELOAD` detection for cmake-built curl binaries

CMake builds by default don't include a triplet in the `curl -V` output,
but a CMake-specific OS string, which is usually capitalized or stylized,
e.g. "Linux", or "FreeBSD". Make the regexp expression case-insensitive
to handle this.

Follow-up to 171b62375965fbf5f02e66f587a83043059ae41a #17653

Closes #17756

diff --git a/tests/runtests.pl b/tests/runtests.pl
index 2708800318048f9e32cf4a831b95412ad1724cbc..8e3b58bd68d32558598bc1ba4f2f52a0b00ff6b8 100755 (executable)
--- a/tests/runtests.pl
+++ b/tests/runtests.pl
@@ -545,7 +545,7 @@ sub checksystemfeatures {
             $curl =~ s/^(.*)(libcurl.*)/$1/g || die "Failure determining curl binary version";
 
             $libcurl = $2;
-            if($curl =~ /linux|bsd|solaris/) {
+            if($curl =~ /linux|bsd|solaris/i) {
                 # system supports LD_PRELOAD/LD_LIBRARY_PATH; may be disabled later
                 $feature{"ld_preload"} = 1;
             }