r15451: Rewrite AC_LIBTESTFUNC so that it works like the callers

of it expect.

diff --git a/source/aclocal.m4 b/source/aclocal.m4
index 67b7017a91061b9a9b94af2e19da38b63d419240..459e4d5c7a0f49055225b573421557871e293a2e 100644 (file)
--- a/source/aclocal.m4
+++ b/source/aclocal.m4
@@ -104,20 +104,32 @@ AC_DEFUN(AC_HAVE_DECL,
 ])
 
 
-dnl Check for a function in a library, but don't
-dnl keep adding the same library to the LIBS variable.
-dnl Check whether the function is available in the current
-dnl LIBS before adding the library. This prevents us spuriously
-dnl finding symbols that are in libc.
-dnl AC_LIBTESTFUNC(lib,func)
+dnl Check for a function in a library, but don't keep adding the same library
+dnl to the LIBS variable.  Check whether the function is available in the
+dnl current LIBS before adding the library which prevents us spuriously
+dnl adding libraries for symbols that are in libc. On success, this ensures that
+dnl HAVE_FOO is defined.
+AC_LIBTESTFUNC(lib,func)
 AC_DEFUN(AC_LIBTESTFUNC,
 [
-  AC_CHECK_FUNCS($2, [],
-      [ case "$LIBS" in
-          *-l$1*) AC_CHECK_FUNCS($2) ;;
-          *) AC_CHECK_LIB($1, $2) 
-             AC_CHECK_FUNCS($2)
-          ;;
+  AC_CHECK_FUNCS($2,
+      [
+        # $2 was found in libc or existing $LIBS
+       AC_DEFINE(translit([HAVE_$2], [a-z], [A-Z]), 1,
+           [Whether $2 is available])
+      ],
+      [
+        # $2 was not found, try adding lib$1
+       case " $LIBS " in
+          *\ -l$1\ *) ;;
+          *) AC_CHECK_LIB($1, $2,
+             [
+               AC_DEFINE(translit([HAVE_$2], [a-z], [A-Z]), 1,
+                   [Whether $2 is available])
+               LIBS="-l$1 $LIBS"
+             ],
+             [])
+         ;;
         esac
       ])
 ])