[PATCH] Change configure to check if pthreads are usable without any extra flags

The configure script checks whether certain flags / libraries are
required to use pthreads. But so far it did not consider the possibility
that no extra compiler flags are needed (as is the case on Mac OS X). As
a result, configure would always add "-mt" to the list of flags. This in
turn triggered a warning in clang about an unknown argument.
To solve this, we now first check if pthreads work without extra flags.

Signed-off-by: Max Horn <redacted>
---
 configure.ac | 2 +-
 1 Datei geändert, 1 Zeile hinzugefügt(+), 1 Zeile entfernt(-)

diff --git a/configure.ac b/configure.ac
index 4e9012f..d767ef3 100644
--- a/configure.ac
+++ b/configure.ac

@@ -1002,7 +1002,7 @@ if test -n "$USER_NOPTHREAD"; then
 # -D_REENTRANT' or some such.
 elif test -z "$PTHREAD_CFLAGS"; then
   threads_found=no
-  for opt in -mt -pthread -lpthread; do
+  for opt in "" -mt -pthread -lpthread; do
      old_CFLAGS="$CFLAGS"
      CFLAGS="$opt $CFLAGS"
      AC_MSG_CHECKING([Checking for POSIX Threads with '$opt'])

-- 
1.7.11.1.145.g4722b29.dirty