Index: cups/dir.c
===================================================================
--- cups/dir.c.orig	2006-09-05 15:45:47.000000000 -0500
+++ cups/dir.c	2006-10-01 22:21:27.472196000 -0500
@@ -40,6 +40,26 @@
  * Include necessary headers...
  */
 
+#include <config.h>
+
+/*
+ * If readdir_r() requires -D_POSIX_PTHREAD_SEMANTICS to work
+ * correctly. Solaris requires this.
+ */
+#ifdef READDIR_R_NEEDS__POSIX_PTHREAD_SEMANTICS
+#define _POSIX_PTHREAD_SEMANTICS
+#endif
+
+/*
+ * If readdir_r() requires -D_REENTRANT to work correctly. HP-UX
+ * 10.20 requires this.
+ */
+
+#ifdef READDIR_R_NEEDS__REENTRANT
+#define _REENTRANT
+#endif
+
+
 #include "dir.h"
 #include "string.h"
 #include "debug.h"
@@ -353,6 +373,10 @@
   char		filename[1024];		/* Full filename */
 
 
+#if READDIR_R_NARGS == 2
+  entry = (struct dirent *)buffer;
+#endif
+
   DEBUG_printf(("cupsDirRead(dp=%p)\n", dp));
 
  /*
@@ -368,7 +392,11 @@
 
   for (;;)
   {
+#if READDIR_R_NARGS == 2
+    if (readdir_r(dp->dir, entry))
+#elif READDIR_R_NARGS == 3
     if (readdir_r(dp->dir, (struct dirent *)buffer, &entry))
+#endif
     {
       DEBUG_printf(("    readdir_r() failed - %s\n", strerror(errno)));
       return (NULL);
Index: config-scripts/cups-common.m4
===================================================================
--- config-scripts/cups-common.m4.orig	2006-09-29 18:39:06.296919000 -0500
+++ config-scripts/cups-common.m4	2006-10-01 21:46:47.641275000 -0500
@@ -176,6 +176,67 @@
 	AC_DEFINE(HAVE_TM_GMTOFF),
 	AC_MSG_RESULT(no))
 
+dnl Number of arguments to readdir_r(). HP-UX 10.20 uses the older
+dnl CMA threads with a readdir_r() accepting two arguments. It
+dnl also requires -D_REENTRANT to expose the readdir_r() prototype.
+AC_MSG_CHECKING(if readdir_r() takes 2 arguments)
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#define _REENTRANT
+#include <stdlib.h>
+#include <sys/types.h>
+#include <dirent.h>
+
+extern int readdir_r(DIR *, struct dirent *);]],[[DIR *dir;
+	struct dirent entry;
+
+	dir = opendir (".");
+	if (!dir)
+		exit (1);
+
+	exit (readdir_r(dir, &entry));]])],[
+		AC_MSG_RESULT(yes)
+		AC_DEFINE(READDIR_R_NARGS, 2)
+		AC_DEFINE(READDIR_R_NEEDS__REENTRANT)],[
+		AC_DEFINE(READDIR_R_NARGS, 3)
+		AC_MSG_RESULT(no)])
+
+dnl See if -D_POSIX_PTHREAD_SEMANTICS required for readdir_r()
+dnl to work correctly. Solaris needs this.
+AC_MSG_CHECKING(if readdir_r() needs -D_POSIX_PTHREAD_SEMANTICS)
+AC_RUN_IFELSE([AC_LANG_PROGRAM([[#include <stdlib.h>
+#include <sys/types.h>
+#include <dirent.h>]],[[DIR *dir;
+	char buffer[sizeof(struct dirent) + 1024];
+	struct dirent *entry;
+
+	dir = opendir (".");
+	if (!dir)
+		exit (1);
+
+	#if READDIR_R_NARGS == 3
+	exit (readdir_r(dir, (struct dirent *)buffer, &entry));
+	#endif]])],[
+		AC_MSG_RESULT(no)],[
+		save_CPPFLAGS=$CPPFLAGS
+		CPPFLAGS="$CPPFLAGS -D_POSIX_PTHREAD_SEMANTICS"
+		AC_RUN_IFELSE([AC_LANG_PROGRAM([[#include <stdlib.h>
+#include <sys/types.h>
+#include <dirent.h>]],[[DIR *dir;
+        char buffer[sizeof(struct dirent) + 1024];
+        struct dirent *entry;
+
+        dir = opendir (".");
+        if (!dir)
+                exit (1);
+
+	#if READDIR_R_NARGS == 3
+        exit (readdir_r(dir, (struct dirent *)buffer, &entry));
+	#endif]])],[
+			AC_MSG_RESULT(yes)
+			AC_DEFINE(READDIR_R_NEEDS__POSIX_PTHREAD_SEMANTICS)],[
+			AC_MSG_RESULT(unknown)
+			AC_MSG_ERROR(readdir_r() non-functional)])
+		CPPFLAGS=$save_CPPFLAGS])
+
 dnl Flags for "ar" command...
 case $uname in
         Darwin* | *BSD*)
Index: config.h.in
===================================================================
--- config.h.in.orig	2006-09-29 18:39:05.067860000 -0500
+++ config.h.in	2006-10-01 21:21:30.122501000 -0500
@@ -442,6 +442,27 @@
 
 #undef ENABLE_IPV6
 
+/*
+ * If readdir_r() requires -D_POSIX_PTHREAD_SEMANTICS to work
+ * correctly. Solaris requires this.
+ */
+
+#undef READDIR_R_NEEDS__POSIX_PTHREAD_SEMANTICS
+
+/*
+ * If readdir_r() requires -D_REENTRANT to work correctly. HP-UX
+ * 10.20 requires this.
+ */
+
+#undef READDIR_R_NEEDS__REENTRANT
+
+/*
+ * Number of arguments to readdir_r(). HP-UX 10.20 uses the older
+ * CMA threads with a readdir_r() accepting two arguments.
+ */
+
+#undef READDIR_R_NARGS
+
 #endif /* !_CUPS_CONFIG_H_ */
 
 /*