* dlopen.c (dlopen): Return NULL when name is NULL (suggested by

chrisiasci@aol.com).
* cygwin.din: Add a new, internally used export - _check_for_executable.
* dcrt0.cc (dll_crt0_1): Set _check_for_executable for older binaries.  Pass
user_data to premain functions.
* fhandler.cc (fhandler_disk_file::open): Only check for executable if the
linked program is intereested in the executable bit.
(fhandler_disk_file::check_execable_p): Delete.
* fhandler.h (executable_states): New enumeration of various states of
executable bit caring.
(fhandler_base::set_execable_p): New method.
* fhandler_termios.cc (fhandler_termios::line_edit): Flag when a signal has
been sent to the tty.  Return -1 when this is so.
* fhandler_console.cc (fhandler_console::read): Return -1 when signal sending
character encountered.
* path.cc (path_conv::check): Record when path refers to a disk device.  Move
executable extension check here.
(check_sysfile): Accomodate new EXEC path states.
(has_suffix): Remove.
(next_suffix): Remove.
(class suffix_scan): New clas.
(suffix_scan::has): New method.
(suffix_scan:next): New method.
(symlink_info::check): Use suffix_scan method to control for scanning for
suffixes.
* path.h (path_conv::exec_state): New method.
* perprocess.h: Make "C" friendly.
* include/cygwin/version.h: Define CYGWIN_VERSION_CHECK_FOR_S_IEXEC.  Bump
CYGWIN_VERSION_API_MINOR.
* include/sys/cygwin.h: Change premain declarations.
* winsup.h: Move __cplusplus test to after builtin defines.

winsup/cygwin/include/cygwin/version.h

@@ -79,7 +79,9 @@ details. */
   (CYGWIN_VERSION_DLL_MAKE_COMBINED (user_data->api_major, user_data->api_minor) <= \
   20)
 
-
+#define CYGWIN_VERSION_CHECK_FOR_S_IEXEC \
+  (CYGWIN_VERSION_DLL_MAKE_COMBINED (user_data->api_major, user_data->api_minor) >= \
+  36)
      /* We used to use the DLL major/minor to track
 	non-backward-compatible interface changes to the API.  Now we
 	use an API major/minor number for this purpose. */
@@ -127,10 +129,11 @@ details. */
        34: Separated out mount table
        35: Export drand48, erand48, jrand48, lcong48, lrand48,
            mrand48, nrand48, seed48, and srand48.
+       36: Added _cygwin_S_IEXEC, et al
      */
 
 #define CYGWIN_VERSION_API_MAJOR 0
-#define CYGWIN_VERSION_API_MINOR 35
+#define CYGWIN_VERSION_API_MINOR 36
 
      /* There is also a compatibity version number associated with the
 	shared memory regions.  It is incremented when incompatible

winsup/cygwin/include/sys/cygwin.h

@@ -31,11 +31,6 @@ extern int cygwin_conv_to_full_posix_path (const char *, char *);
 extern int cygwin_posix_path_list_p (const char *);
 extern void cygwin_split_path (const char *, char *, char *);
 
-extern void cygwin_premain0 (int argc, char **argv);
-extern void cygwin_premain1 (int argc, char **argv);
-extern void cygwin_premain2 (int argc, char **argv);
-extern void cygwin_premain3 (int argc, char **argv);
-
 struct __cygwin_perfile
 {
   const char *name;
@@ -149,7 +144,7 @@ struct per_process
 
   void *(*calloc)(size_t, size_t);
   /* For future expansion of values set by the app. */
-  void (*premain[4]) (int, char **);
+  void (*premain[4]) (int, char **, struct per_process *);
 
   /* The rest are *internal* to cygwin.dll.
      Those that are here because we want the child to inherit the value from
@@ -165,7 +160,7 @@ struct per_process
   void *heapptr;		/* current index into heap */
   void *heaptop;		/* current top of heap */
 
-  DWORD unused1;		/* unused */
+  DWORD unused1;
 
   /* Non-zero means the task was forked.  The value is the pid.
      Inherited from parent. */
@@ -190,6 +185,11 @@ struct per_process
 };
 #define per_process_overwrite ((unsigned) &(((struct per_process *) NULL)->resourcelocks))
 
+extern void cygwin_premain0 (int argc, char **argv, struct per_process *);
+extern void cygwin_premain1 (int argc, char **argv, struct per_process *);
+extern void cygwin_premain2 (int argc, char **argv, struct per_process *);
+extern void cygwin_premain3 (int argc, char **argv, struct per_process *);
+
 extern void cygwin_set_impersonation_token (const HANDLE);
 
 /* included if <windows.h> is included */

winsup/cygwin/include/sys/file.h

@@ -24,7 +24,13 @@
 
 
 #define	F_OK		0	/* does file exist */
-#define	X_OK		1	/* is it executable by caller */
+#define	_X_OK		1	/* is it executable by caller */
+#if defined (__CYGWIN__) || defined (__INSIDE_CYGWIN__)
+# define X_OK	_X_OK	/* Check for execute permission. */
+#else
+extern const unsigned _cygwin_X_OK;
+# define X_OK	_cygwin_X_OK
+#endif
 #define	W_OK		2	/* is it writable by caller */
 #define	R_OK		4	/* is it readable by caller */