Restore functionality on Windows 98

* configure.ac (W32_LIBS): Don't link with -lusp10 on non-Cygwin
systems.

* src/emacs.c (main): Call globals_of_w32 before the startup
directory is initialized.

* src/w32.c (maybe_load_unicows_dll): Call
load_unicows_dll_for_w32fns.

* src/w32.h: Update prototypes.

* src/w32fns.c (Fx_create_frame, w32_create_tip_frame): Do not
register the Uniscribe font driver when unavailable.
(pfnSHFileOperationW): New function pointer.
(Fsystem_move_file_to_trash): Load UNICOWS.DLL if not yet
loaded.  Call SHFileOperationW through said function pointer.
(pfnShellExecuteExW): New function pointer.
(Fw32_shell_execute) [!CYGWIN]: Load UNICOWS.DLL if not yet
loaded.  Call ShellExecuteExW through said function pointer.
(pfnShell_NotifyIconW): New function pointer.
(add_tray_notification, delete_tray_notification): Call
Shell_NotifyIconW through said function pointer.
(Fw32_notification_notify): Load UNICOWS.DLL.
(Fw32_notification_close): Return if Shell_NotifyIconW is
unavailable, as when UNICOWS.DLL has yet to be loaded.
(load_unicows_dll_for_w32fns): New function.

* src/w32notify.c (pfnReadDirectoryChangesW): New function
pointer.
(watch_completion, remove_watch, Fw32notify_add_watch)
(Fw32notify_rm_watch, Fw32notify_valid_p): Call
ReadDirectoryChangesW through said function pointer, and assert
its presence.
(globals_of_w32notify): Load ReadDirectoryChangesW from
KERNEL32.DLL.

* src/w32uniscribe.c (pfnScriptItemize, pfnScriptShape)
(pfnScriptPlace, pfnScriptGetGlyphABCWidth, pfnScriptFreeCache)
(pfnScriptGetCMap): New function pointers.
(uniscribe_close, uniscribe_shape, uniscribe_encode_char)
(uniscribe_check_otf_1): Call Uniscribe functions through the
same.
(syms_of_w32uniscribe_for_pdumper): Load Uniscribe library and
required functions from the same, and if unavailable, return
while leaving uniscribe_available intact.  On Cygwin, simply
assign USP10.DLL functions to the said new function pointers.

1 files changed, 29 insertions, 13 deletions

diff --git a/src/w32notify.c b/src/w32notify.c
index c93e8796fe2..1001c85fdbe 100644
--- a/src/w32notify.c
+++ b/src/w32notify.c
@@ -120,6 +120,10 @@ struct notification {
 /* Used for communicating notifications to the main thread.  */
 struct notifications_set *notifications_set_head;
 
+/* Function pointers.  */
+static BOOL (WINAPI *pfnReadDirectoryChangesW) (HANDLE, PVOID, DWORD, BOOL,
+                                                DWORD, PDWORD, LPOVERLAPPED,
+                                                LPOVERLAPPED_COMPLETION_ROUTINE);
 static Lisp_Object watch_list;
 
 /* Signal to the main thread that we have file notifications for it to
@@ -252,10 +256,10 @@ watch_completion (DWORD status, DWORD bytes_ret, OVERLAPPED *io_info)
 
   /* Calling ReadDirectoryChangesW quickly to watch again for new
      notifications.  */
-  if (!ReadDirectoryChangesW (dirwatch->dir, dirwatch->buf,
-                              DIRWATCH_BUFFER_SIZE, dirwatch->subtree,
-                              dirwatch->filter, &_bytes, dirwatch->io_info,
-                              watch_completion))
+  if (!(*pfnReadDirectoryChangesW) (dirwatch->dir, dirwatch->buf,
+                                    DIRWATCH_BUFFER_SIZE, dirwatch->subtree,
+                                    dirwatch->filter, &_bytes,
+                                    dirwatch->io_info, watch_completion))
     {
       DebPrint (("ReadDirectoryChangesW error: %lu\n", GetLastError ()));
       /* If this call fails, it means that the directory is not
@@ -270,7 +274,7 @@ watch_completion (DWORD status, DWORD bytes_ret, OVERLAPPED *io_info)
 
   /* If we were asked to terminate the thread, then fire the event. */
   if (terminate)
-    SetEvent(dirwatch->terminate);
+    SetEvent (dirwatch->terminate);
 }
 
 /* Worker routine for the watch thread.  */
@@ -284,10 +288,10 @@ watch_worker (LPVOID arg)
 
   if (dirwatch->dir)
     {
-      bErr = ReadDirectoryChangesW (dirwatch->dir, dirwatch->buf,
-                                    DIRWATCH_BUFFER_SIZE, dirwatch->subtree,
-                                    dirwatch->filter, &_bytes,
-                                    dirwatch->io_info, watch_completion);
+      bErr = (*pfnReadDirectoryChangesW) (dirwatch->dir, dirwatch->buf,
+                                          DIRWATCH_BUFFER_SIZE, dirwatch->subtree,
+                                          dirwatch->filter, &_bytes,
+                                          dirwatch->io_info, watch_completion);
       if (!bErr)
         {
           DebPrint (("ReadDirectoryChangesW: %lu\n", GetLastError ()));
@@ -436,7 +440,7 @@ remove_watch (struct notification *dirwatch)
         DebPrint (("QueueUserAPC failed (%lu)!\n", GetLastError ()));
 
       /* We also signal the thread that it can terminate.  */
-      SetEvent(dirwatch->terminate);
+      SetEvent (dirwatch->terminate);
 
       /* Wait for the thread to exit.  FIXME: is there a better method
          that is not overly complex?  */
@@ -466,7 +470,7 @@ remove_watch (struct notification *dirwatch)
           CloseHandle (dirwatch->thr);
           dirwatch->thr = NULL;
         }
-      CloseHandle(dirwatch->terminate);
+      CloseHandle (dirwatch->terminate);
       xfree (dirwatch->buf);
       xfree (dirwatch->io_info);
       xfree (dirwatch->watchee);
@@ -575,6 +579,8 @@ generate notifications correctly, though.  */)
       report_file_notify_error ("Watching filesystem events is not supported",
                                 Qnil);
     }
+  else
+    eassert (pfnReadDirectoryChangesW);
 
   /* filenotify.el always passes us a directory, either the parent
      directory of a file to be watched, or the directory to be
@@ -649,7 +655,7 @@ WATCH-DESCRIPTOR should be an object returned by `w32notify-add-watch'.  */)
   if (!NILP (watch_object))
     {
       watch_list = Fdelete (watch_object, watch_list);
-      dirwatch = (struct notification *)xmint_pointer (watch_descriptor);
+      dirwatch = (struct notification *) xmint_pointer (watch_descriptor);
       if (w32_valid_pointer_p (dirwatch, sizeof(struct notification)))
         status = remove_watch (dirwatch);
     }
@@ -687,7 +693,7 @@ watch by calling `w32notify-rm-watch' also makes it invalid.  */)
   if (!NILP (watch_object))
     {
       struct notification *dirwatch =
-        (struct notification *)xmint_pointer (watch_descriptor);
+        (struct notification *) xmint_pointer (watch_descriptor);
       if (w32_valid_pointer_p (dirwatch, sizeof(struct notification))
           && dirwatch->dir != NULL)
         return Qt;
@@ -699,6 +705,16 @@ watch by calling `w32notify-rm-watch' also makes it invalid.  */)
 void
 globals_of_w32notify (void)
 {
+  HANDLE kernel32 = GetModuleHandle ("kernel32");
+
+  /* Initialize pointers to IO functions that provide file
+     notifications.  In the event that these are absent, no harm will be
+     done, since their absence indicates that Emacs is running on
+     Windows 9X, where file notifications are unavailable at the
+     outset.  */
+  pfnReadDirectoryChangesW
+    = (void *) get_proc_addr (kernel32, "ReadDirectoryChangesW");
+
   watch_list = Qnil;
 }