configure: add "-mt" for pthread support on HP-UX

HP-UX requires this compiler and linker flag to pass proper macros and
add required libraries.

Closes #18585

diff --git a/configure.ac b/configure.ac
index af005beffd12b6d4250c403c1f729377158f3886..3f02d037ef3dfbb3c30165bb80688dd4287a6b03 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -4340,11 +4340,9 @@ if test "$want_threaded_resolver" = "yes" && test "$USE_THREADS_WIN32" != "1"; t
       AC_CHECK_FUNC(pthread_create, [USE_THREADS_POSIX=1] )
       LIBS="$save_LIBS"
 
-      dnl on HP-UX, life is more complicated...
       case $host in
         *-hp-hpux*)
-          dnl it doesn't actually work without -lpthread
-          USE_THREADS_POSIX=""
+          CFLAGS="$CFLAGS -mt"
           ;;
         *)
           ;;