Revision: miles@gnu.org--gnu-2005/emacs--unicode--0--patch-67

Merge from emacs--cvs-trunk--0

Patches applied:

 * emacs--cvs-trunk--0  (patch 447-458)

   - Update from CVS
   - Update from CVS: lisp/subr.el (add-to-ordered-list): Doc fix.
   - Merge from gnus--rel--5.10

 * gnus--rel--5.10  (patch 83-85)

   - Merge from emacs--cvs-trunk--0
   - Update from CVS

12 files changed, 291 insertions, 96 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 94cfec41a62..2d312756daf 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,11 +1,80 @@
+2005-06-29  Juanma Barranquero  <lekktu@gmail.com>
+
+	* eval.c (user_variable_p_eh): New function.
+	(Fuser_variable_p): Use it.  Clarify docstring.
+	Return t for aliases of user options, nil for alias loops.
+
+2005-06-27  Richard M. Stallman  <rms@gnu.org>
+
+	* eval.c (Fdefvar): Improve error message.
+
+2005-06-27  YAMAMOTO Mitsuharu  <mituharu@math.s.chiba-u.ac.jp>
+
+	* macterm.c [USE_CARBON_EVENTS] (mac_convert_event_ref): Fix last
+	change.
+
+2005-06-27  Juanma Barranquero  <lekktu@gmail.com>
+
+	* eval.c (Fdefvar): Don't try to set constant symbols.
+
+2005-06-25  Richard M. Stallman  <rms@gnu.org>
+
+	* macfns.c (Fx_show_tip): Pass new arg to try_window.
+
+	* w32fns.c (Fx_show_tip): Pass new arg to try_window.
+
+	* xfns.c (Fx_show_tip): Pass new arg to try_window.
+
+	* xdisp.c (try_window): New arg CHECK_MARGINS.  Calls changed.
+	(redisplay_window): Handle try_window reporting point in scroll margin.
+
+	* dispextern.h (try_window): Declare new arg.
+
+	* fileio.c (Fcopy_file): New arg PRESERVE_UID_GID.
+	Use fchmod to copy the file modes.
+	(Frename_file): Don't copy UID and GID here;
+	instead, specify t for PRESERVE_UID_GID when calling Fcopy_file.
+
+	* eval.c (call_debugger): Take full care of extending stack limits
+	to make space for the debugger, and restore the change afterward.
+	Bind debug-on-error to nil.
+	(restore_stack_limits): New subroutine.
+	(Fsignal): Extend specpdl bound along with eval depth bound,
+	for calling edebug.  Don't do either one, for calling debugger.
+	(find_handler_clause): Don't bind debug-on-error here.
+	Don't unbind anything either.
+	Temporarily advance max_specpdl_size for calling
+	internal_with_output_to_temp_buffer.
+	(grow_specpdl): Don't alter max_specpdl_size before signaling
+	an error.
+	(syms_of_eval) <max-specpdl-size>: Doc fix.
+
+	* lread.c (read1): 0.0e+NaN should make a "positive" NaN.
+
+2005-06-24  Eli Zaretskii  <eliz@gnu.org>
+
+	* fileio.c (Frename_file): Undo last change: no need to ifdef away
+	chown on DOS_NT platforms.
+
+	* w32.c (sys_chown): New function.
+
+	* s/ms-w32.h (chown): New; define to sys_chown.
+
+2005-06-24  Juanma Barranquero  <lekktu@gmail.com>
+
+	* xdisp.c (syms_of_xdisp) <nobreak-char-display>: Doc fix.
+	(syms_of_xdisp) <void-text-area-pointer>: Doc fix.
+
+	* fileio.c (Frename_file)[!DOS_NT]: Don't call chown on MSDOS/Windows.
+
 2005-06-23  Richard M. Stallman  <rms@gnu.org>
 
 	* xdisp.c (get_next_display_element): Finish reversing the tests of
 	Vnobreak_char_display.
 
-	* xdisp.c (Vnobreak_char_display): Renamed from Vshow_nonbreak_escape.
+	* xdisp.c (Vnobreak_char_display): Rename from Vshow_nonbreak_escape.
 	All uses changed.
-	(Qnobreak_space): Renamed from Qno_break_space.  All uses changed.
+	(Qnobreak_space): Rename from Qno_break_space.  All uses changed.
 	(syms_of_xdisp): Define nobreak-char-display and nobreak-space.
 
 	* fileio.c (Frename_file): Preserve owner and group, if possible,
@@ -301,8 +370,7 @@
 
 2005-06-06  Eli Zaretskii  <eliz@gnu.org>
 
-	* w32heap.h (OFFSET_TO_RVA, RVA_TO_OFFSET, RVA_TO_PTR):
-	Remove macros.
+	* w32heap.h (OFFSET_TO_RVA, RVA_TO_OFFSET, RVA_TO_PTR): Remove macros.
 
 	* unexw32.c (RVA_TO_PTR): Move here from w32heap.h.
 
diff --git a/src/dispextern.h b/src/dispextern.h
index cd8488830f0..c049b17ce56 100644
--- a/src/dispextern.h
+++ b/src/dispextern.h
@@ -2589,7 +2589,7 @@ int line_bottom_y P_ ((struct it *));
 int display_prop_intangible_p P_ ((Lisp_Object));
 void resize_echo_area_exactly P_ ((void));
 int resize_mini_window P_ ((struct window *, int));
-int try_window P_ ((Lisp_Object, struct text_pos));
+int try_window P_ ((Lisp_Object, struct text_pos, int));
 void window_box P_ ((struct window *, int, int *, int *, int *, int *));
 int window_box_height P_ ((struct window *));
 int window_text_bottom_y P_ ((struct window *));
diff --git a/src/eval.c b/src/eval.c
index 8ad289fd51f..17e9f7f4360 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -227,6 +227,18 @@ init_eval ()
   when_entered_debugger = -1;
 }
 
+/* unwind-protect function used by call_debugger.  */
+
+static Lisp_Object
+restore_stack_limits (data)
+     Lisp_Object data;
+{
+  max_specpdl_size = XINT (XCAR (data));
+  max_lisp_eval_depth = XINT (XCDR (data));
+}
+
+/* Call the Lisp debugger, giving it argument ARG.  */
+
 Lisp_Object
 call_debugger (arg)
      Lisp_Object arg;
@@ -234,12 +246,22 @@ call_debugger (arg)
   int debug_while_redisplaying;
   int count = SPECPDL_INDEX ();
   Lisp_Object val;
+  int old_max = max_specpdl_size;
+
+  /* Temporarily bump up the stack limits,
+     so the debugger won't run out of stack.  */
+
+  max_specpdl_size += 1;
+  record_unwind_protect (restore_stack_limits,
+			 Fcons (make_number (old_max),
+				make_number (max_lisp_eval_depth)));
+  max_specpdl_size = old_max;
 
-  if (lisp_eval_depth + 20 > max_lisp_eval_depth)
-    max_lisp_eval_depth = lisp_eval_depth + 20;
+  if (lisp_eval_depth + 40 > max_lisp_eval_depth)
+    max_lisp_eval_depth = lisp_eval_depth + 40;
 
-  if (specpdl_size + 40 > max_specpdl_size)
-    max_specpdl_size = specpdl_size + 40;
+  if (SPECPDL_INDEX () + 100 > max_specpdl_size)
+    max_specpdl_size = SPECPDL_INDEX () + 100;
 
 #ifdef HAVE_X_WINDOWS
   if (display_hourglass_p)
@@ -256,6 +278,7 @@ call_debugger (arg)
   specbind (intern ("debugger-may-continue"),
 	    debug_while_redisplaying ? Qnil : Qt);
   specbind (Qinhibit_redisplay, Qnil);
+  specbind (Qdebug_on_error, Qnil);
 
 #if 0 /* Binding this prevents execution of Lisp code during
 	 redisplay, which necessarily leads to display problems.  */
@@ -783,6 +806,10 @@ usage: (defvar SYMBOL &optional INITVALUE DOCSTRING)  */)
   register Lisp_Object sym, tem, tail;
 
   sym = Fcar (args);
+  if (SYMBOL_CONSTANT_P (sym))
+    error ("Constant symbol `%s' specified in defvar",
+           SDATA (SYMBOL_NAME (sym)));
+
   tail = Fcdr (args);
   if (!NILP (Fcdr (Fcdr (tail))))
     error ("Too many arguments");
@@ -862,12 +889,24 @@ usage: (defconst SYMBOL INITVALUE [DOCSTRING])  */)
   return sym;
 }
 
+/* Error handler used in Fuser_variable_p.  */
+static Lisp_Object
+user_variable_p_eh (ignore)
+     Lisp_Object ignore;
+{
+  return Qnil;
+}
+
 DEFUN ("user-variable-p", Fuser_variable_p, Suser_variable_p, 1, 1, 0,
-       doc: /* Returns t if VARIABLE is intended to be set and modified by users.
+       doc: /* Return t if VARIABLE is intended to be set and modified by users.
 \(The alternative is a variable used internally in a Lisp program.)
-Determined by whether the first character of the documentation
-for the variable is `*' or if the variable is customizable (has a non-nil
-value of `standard-value' or of `custom-autoload' on its property list).  */)
+A variable is a user variable if
+\(1) the first character of its documentation is `*', or
+\(2) it is customizable (its property list contains a non-nil value
+    of `standard-value' or `custom-autoload'), or
+\(3) it is an alias for another user variable.
+Return nil if VARIABLE is an alias and there is a loop in the
+chain of symbols.  */)
      (variable)
      Lisp_Object variable;
 {
@@ -876,23 +915,37 @@ value of `standard-value' or of `custom-autoload' on its property list).  */)
   if (!SYMBOLP (variable))
       return Qnil;
 
-  documentation = Fget (variable, Qvariable_documentation);
-  if (INTEGERP (documentation) && XINT (documentation) < 0)
-    return Qt;
-  if (STRINGP (documentation)
-      && ((unsigned char) SREF (documentation, 0) == '*'))
-    return Qt;
-  /* If it is (STRING . INTEGER), a negative integer means a user variable.  */
-  if (CONSP (documentation)
-      && STRINGP (XCAR (documentation))
-      && INTEGERP (XCDR (documentation))
-      && XINT (XCDR (documentation)) < 0)
-    return Qt;
-  /* Customizable?  See `custom-variable-p'. */
-  if ((!NILP (Fget (variable, intern ("standard-value"))))
-      || (!NILP (Fget (variable, intern ("custom-autoload")))))
-    return Qt;
-  return Qnil;
+  /* If indirect and there's an alias loop, don't check anything else.  */
+  if (XSYMBOL (variable)->indirect_variable
+      && NILP (internal_condition_case_1 (indirect_variable, variable,
+                                          Qt, user_variable_p_eh)))
+    return Qnil;
+
+  while (1)
+    {
+      documentation = Fget (variable, Qvariable_documentation);
+      if (INTEGERP (documentation) && XINT (documentation) < 0)
+        return Qt;
+      if (STRINGP (documentation)
+          && ((unsigned char) SREF (documentation, 0) == '*'))
+        return Qt;
+      /* If it is (STRING . INTEGER), a negative integer means a user variable.  */
+      if (CONSP (documentation)
+          && STRINGP (XCAR (documentation))
+          && INTEGERP (XCDR (documentation))
+          && XINT (XCDR (documentation)) < 0)
+        return Qt;
+      /* Customizable?  See `custom-variable-p'.  */
+      if ((!NILP (Fget (variable, intern ("standard-value"))))
+          || (!NILP (Fget (variable, intern ("custom-autoload")))))
+        return Qt;
+
+      if (!XSYMBOL (variable)->indirect_variable)
+        return Qnil;
+
+      /* An indirect variable?  Let's follow the chain.  */
+      variable = XSYMBOL (variable)->value;
+    }
 }
 
 DEFUN ("let*", FletX, SletX, 1, UNEVALLED, 0,
@@ -1533,7 +1586,16 @@ See also the function `condition-case'.  */)
   /* This hook is used by edebug.  */
   if (! NILP (Vsignal_hook_function)
       && ! NILP (error_symbol))
-    call2 (Vsignal_hook_function, error_symbol, data);
+    {
+      /* Edebug takes care of restoring these variables when it exits.  */
+      if (lisp_eval_depth + 20 > max_lisp_eval_depth)
+	max_lisp_eval_depth = lisp_eval_depth + 20;
+
+      if (SPECPDL_INDEX () + 40 > max_specpdl_size)
+	max_specpdl_size = SPECPDL_INDEX () + 40;
+
+      call2 (Vsignal_hook_function, error_symbol, data);
+    }
 
   conditions = Fget (real_error_symbol, Qerror_conditions);
 
@@ -1555,12 +1617,6 @@ See also the function `condition-case'.  */)
     {
       register Lisp_Object clause;
 
-      if (lisp_eval_depth + 20 > max_lisp_eval_depth)
-	max_lisp_eval_depth = lisp_eval_depth + 20;
-
-      if (specpdl_size + 40 > max_specpdl_size)
-	max_specpdl_size = specpdl_size + 40;
-
       clause = find_handler_clause (handlerlist->handler, conditions,
 				    error_symbol, data, &debugger_value);
 
@@ -1673,7 +1729,11 @@ skip_debugger (conditions, data)
     = SIG is nil, and DATA is (SYMBOL . REST-OF-DATA).
        This is for memory-full errors only.
 
-   Store value returned from debugger into *DEBUGGER_VALUE_PTR.  */
+   Store value returned from debugger into *DEBUGGER_VALUE_PTR.
+
+   We need to increase max_specpdl_size temporarily around
+   anything we do that can push on the specpdl, so as not to get
+   a second error here in case we're handling specpdl overflow.  */
 
 static Lisp_Object
 find_handler_clause (handlers, conditions, sig, data, debugger_value_ptr)
@@ -1691,7 +1751,6 @@ find_handler_clause (handlers, conditions, sig, data, debugger_value_ptr)
       || !NILP (Vdebug_on_signal)) /* This says call debugger even if
 				      there is a handler.  */
     {
-      int count = SPECPDL_INDEX ();
       int debugger_called = 0;
       Lisp_Object sig_symbol, combined_data;
       /* This is set to 1 if we are handling a memory-full error,
@@ -1713,6 +1772,7 @@ find_handler_clause (handlers, conditions, sig, data, debugger_value_ptr)
 
       if (wants_debugger (Vstack_trace_on_error, conditions))
 	{
+	  max_specpdl_size++;
 #ifdef PROTOTYPES
 	  internal_with_output_to_temp_buffer ("*Backtrace*",
 					       (Lisp_Object (*) (Lisp_Object)) Fbacktrace,
@@ -1721,6 +1781,7 @@ find_handler_clause (handlers, conditions, sig, data, debugger_value_ptr)
 	  internal_with_output_to_temp_buffer ("*Backtrace*",
 					       Fbacktrace, Qnil);
 #endif
+	  max_specpdl_size--;
 	}
       if (! no_debugger
 	  && (EQ (sig_symbol, Qquit)
@@ -1729,7 +1790,6 @@ find_handler_clause (handlers, conditions, sig, data, debugger_value_ptr)
 	  && ! skip_debugger (conditions, combined_data)
 	  && when_entered_debugger < num_nonmacro_input_events)
 	{
-	  specbind (Qdebug_on_error, Qnil);
 	  *debugger_value_ptr
 	    = call_debugger (Fcons (Qerror,
 				    Fcons (combined_data, Qnil)));
@@ -1739,7 +1799,7 @@ find_handler_clause (handlers, conditions, sig, data, debugger_value_ptr)
       if (EQ (handlers, Qerror))
 	{
 	  if (debugger_called)
-	    return unbind_to (count, Qlambda);
+	    return Qlambda;
 	  return Qt;
 	}
     }
@@ -3019,13 +3079,8 @@ grow_specpdl ()
       if (max_specpdl_size < 400)
 	max_specpdl_size = 400;
       if (specpdl_size >= max_specpdl_size)
-	{
-	  if (!NILP (Vdebug_on_error))
-	    /* Leave room for some specpdl in the debugger.  */
-	    max_specpdl_size = specpdl_size + 100;
-	  Fsignal (Qerror,
-		   Fcons (build_string ("Variable binding depth exceeds max-specpdl-size"), Qnil));
-	}
+	Fsignal (Qerror,
+		 Fcons (build_string ("Variable binding depth exceeds max-specpdl-size"), Qnil));
     }
   specpdl_size *= 2;
   if (specpdl_size > max_specpdl_size)
@@ -3333,7 +3388,7 @@ syms_of_eval ()
 {
   DEFVAR_INT ("max-specpdl-size", &max_specpdl_size,
 	      doc: /* *Limit on number of Lisp variable bindings & unwind-protects.
-If Lisp code tries to make more than this many at once,
+If Lisp code tries to increase the total number past this amount,
 an error is signaled.
 You can safely use a value considerably larger than the default value,
 if that proves inconveniently small.  However, if you increase it too far,
diff --git a/src/fileio.c b/src/fileio.c
index 3dab52c47f0..112c879c1c5 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -2411,7 +2411,7 @@ barf_or_query_if_file_exists (absname, querystring, interactive, statptr, quick)
   return;
 }
 
-DEFUN ("copy-file", Fcopy_file, Scopy_file, 2, 5,
+DEFUN ("copy-file", Fcopy_file, Scopy_file, 2, 6,
        "fCopy file: \nGCopy %s to file: \np\nP",
        doc: /* Copy FILE to NEWNAME.  Both args must be strings.
 If NEWNAME names a directory, copy FILE there.
@@ -2431,9 +2431,13 @@ for an existing file with the same name.  If MUSTBENEW is `excl',
 that means to get an error if the file already exists; never overwrite.
 If MUSTBENEW is neither nil nor `excl', that means ask for
 confirmation before overwriting, but do go ahead and overwrite the file
-if the user confirms.  */)
-  (file, newname, ok_if_already_exists, keep_time, mustbenew)
+if the user confirms.
+
+If PRESERVE-UID-GID is non-nil, we try to transfer the
+uid and gid of FILE to NEWNAME.  */)
+  (file, newname, ok_if_already_exists, keep_time, mustbenew, preserve_uid_gid)
      Lisp_Object file, newname, ok_if_already_exists, keep_time, mustbenew;
+     Lisp_Object preserve_uid_gid;
 {
   int ifd, ofd, n;
   char buf[16 * 1024];
@@ -2575,6 +2579,26 @@ if the user confirms.  */)
       report_file_error ("I/O error", Fcons (newname, Qnil));
   immediate_quit = 0;
 
+  /* Preserve the owner and group, if requested.  */
+  if (input_file_statable_p && ! NILP (preserve_uid_gid))
+    fchown (ofd, st.st_uid, st.st_gid);
+
+  if (input_file_statable_p)
+    {
+#ifndef MSDOS
+      fchmod (ofd, st.st_mode & 07777);
+#else /* MSDOS */
+#if defined (__DJGPP__) && __DJGPP__ > 1
+      /* In DJGPP v2.0 and later, fstat usually returns true file mode bits,
+         and if it can't, it tells so.  Otherwise, under MSDOS we usually
+         get only the READ bit, which will make the copied file read-only,
+         so it's better not to chmod at all.  */
+      if ((_djstat_flags & _STFAIL_WRITEBIT) == 0)
+	chmod (SDATA (encoded_newname), st.st_mode & 07777);
+#endif /* DJGPP version 2 or newer */
+#endif /* MSDOS */
+    }
+
   /* Closing the output clobbers the file times on some systems.  */
   if (emacs_close (ofd) < 0)
     report_file_error ("I/O error", Fcons (newname, Qnil));
@@ -2592,18 +2616,6 @@ if the user confirms.  */)
 		     Fcons (build_string ("Cannot set file date"),
 			    Fcons (newname, Qnil)));
 	}
-#ifndef MSDOS
-      chmod (SDATA (encoded_newname), st.st_mode & 07777);
-#else /* MSDOS */
-#if defined (__DJGPP__) && __DJGPP__ > 1
-      /* In DJGPP v2.0 and later, fstat usually returns true file mode bits,
-         and if it can't, it tells so.  Otherwise, under MSDOS we usually
-         get only the READ bit, which will make the copied file read-only,
-         so it's better not to chmod at all.  */
-      if ((_djstat_flags & _STFAIL_WRITEBIT) == 0)
-	chmod (SDATA (encoded_newname), st.st_mode & 07777);
-#endif /* DJGPP version 2 or newer */
-#endif /* MSDOS */
     }
 
   emacs_close (ifd);
@@ -2780,7 +2792,6 @@ This is what happens in interactive use with M-x.  */)
     {
       if (errno == EXDEV)
 	{
-	  struct stat data;
 #ifdef S_IFLNK
           symlink_target = Ffile_symlink_p (file);
           if (! NILP (symlink_target))
@@ -2788,15 +2799,11 @@ This is what happens in interactive use with M-x.  */)
                                  NILP (ok_if_already_exists) ? Qnil : Qt);
           else
 #endif
-            Fcopy_file (file, newname,
-                        /* We have already prompted if it was an integer,
-                           so don't have copy-file prompt again.  */
-                        NILP (ok_if_already_exists) ? Qnil : Qt,
-			Qt, Qnil);
-
-	  /* Preserve owner and group, if possible (if we are root).  */
-	  if (stat (SDATA (encoded_file), &data) >= 0)
-	    chown (SDATA (encoded_file), data.st_uid, data.st_gid);
+	    Fcopy_file (file, newname,
+			/* We have already prompted if it was an integer,
+			   so don't have copy-file prompt again.  */
+			NILP (ok_if_already_exists) ? Qnil : Qt,
+			Qt, Qnil, Qt);
 
 	  Fdelete_file (file);
 	}
diff --git a/src/lread.c b/src/lread.c
index d180836ada3..389bc04ddaa 100644
--- a/src/lread.c
+++ b/src/lread.c
@@ -2715,6 +2715,23 @@ read1 (readcharfun, pch, first_in_list)
 		    break;
 		  case 'N':
 		    value = zero / zero;
+
+		    /* If that made a "negative" NaN, negate it.  */
+
+		    {
+		      int i;
+		      union { double d; char c[sizeof (double)]; } u_data, u_minus_zero;
+
+		      u_data.d = value;
+		      u_minus_zero.d = - 0.0;
+		      for (i = 0; i < sizeof (double); i++)
+			if (u_data.c[i] & u_minus_zero.c[i])
+			  {
+			    value = - value;
+			    break;
+			  }
+		    }
+		    /* Now VALUE is a positive NaN.  */
 		    break;
 		  default:
 		    value = atof (read_buffer + negative);
diff --git a/src/macfns.c b/src/macfns.c
index 346ee1e2bde..f6ce7c42a67 100644
--- a/src/macfns.c
+++ b/src/macfns.c
@@ -4088,7 +4088,7 @@ Text larger than the specified size is clipped.  */)
   clear_glyph_matrix (w->desired_matrix);
   clear_glyph_matrix (w->current_matrix);
   SET_TEXT_POS (pos, BEGV, BEGV_BYTE);
-  try_window (FRAME_ROOT_WINDOW (f), pos);
+  try_window (FRAME_ROOT_WINDOW (f), pos, 0);
 
   /* Compute width and height of the tooltip.  */
   width = height = 0;
diff --git a/src/macterm.c b/src/macterm.c
index cef213024fa..16d8452c87c 100644
--- a/src/macterm.c
+++ b/src/macterm.c
@@ -7666,6 +7666,7 @@ static Boolean mac_convert_event_ref (EventRef eventRef, EventRecord *eventRec)
 	default:
 	  break;
 	}
+      break;
 
     case kEventClassKeyboard:
       switch (GetEventKind (eventRef))
@@ -7688,6 +7689,7 @@ static Boolean mac_convert_event_ref (EventRef eventRef, EventRecord *eventRec)
 	default:
 	  break;
 	}
+      break;
 
     default:
       break;
diff --git a/src/s/ms-w32.h b/src/s/ms-w32.h
index 998c1f7cf05..10e3bfe3a5a 100644
--- a/src/s/ms-w32.h
+++ b/src/s/ms-w32.h
@@ -311,6 +311,7 @@ Boston, MA 02111-1307, USA.  */
 #define chdir   sys_chdir
 #undef chmod
 #define chmod   sys_chmod
+#define chown   sys_chown
 #undef close
 #define close   sys_close
 #undef creat
diff --git a/src/w32.c b/src/w32.c
index 1bb4a91ff03..1585b3eaf1e 100644
--- a/src/w32.c
+++ b/src/w32.c
@@ -1898,6 +1898,14 @@ sys_chmod (const char * path, int mode)
 }
 
 int
+sys_chown (const char *path, uid_t owner, gid_t group)
+{
+  if (sys_chmod (path, _S_IREAD) == -1) /* check if file exists */
+    return -1;
+  return 0;
+}
+
+int
 sys_creat (const char * path, int mode)
 {
   return _creat (map_w32_filename (path, NULL), mode);
diff --git a/src/w32fns.c b/src/w32fns.c
index 3913349d8bd..5d92cb03d00 100644
--- a/src/w32fns.c
+++ b/src/w32fns.c
@@ -7648,7 +7648,7 @@ Text larger than the specified size is clipped.  */)
   clear_glyph_matrix (w->desired_matrix);
   clear_glyph_matrix (w->current_matrix);
   SET_TEXT_POS (pos, BEGV, BEGV_BYTE);
-  try_window (FRAME_ROOT_WINDOW (f), pos);
+  try_window (FRAME_ROOT_WINDOW (f), pos, 0);
 
   /* Compute width and height of the tooltip.  */
   width = height = 0;
diff --git a/src/xdisp.c b/src/xdisp.c
index b5f69a93810..0a2a02b4628 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -7697,7 +7697,7 @@ display_echo_area_1 (a1, a2, a3, a4)
   clear_glyph_matrix (w->desired_matrix);
   XSETWINDOW (window, w);
   SET_TEXT_POS (start, BEG, BEG_BYTE);
-  try_window (window, start);
+  try_window (window, start, 0);
 
   return window_height_changed_p;
 }
@@ -11665,7 +11665,7 @@ try_scrolling (window, just_this_one_p, scroll_conservatively,
 
   /* Display the window.  Give up if new fonts are loaded, or if point
      doesn't appear.  */
-  if (!try_window (window, startp))
+  if (!try_window (window, startp, 0))
     rc = SCROLLING_NEED_LARGER_MATRICES;
   else if (w->cursor.vpos < 0)
     {
@@ -12268,6 +12268,7 @@ redisplay_window (window, just_this_one_p)
     {
       /* We set this later on if we have to adjust point.  */
       int new_vpos = -1;
+      int val;
 
       w->force_start = Qnil;
       w->vscroll = 0;
@@ -12301,12 +12302,16 @@ redisplay_window (window, just_this_one_p)
 
       /* Redisplay, then check if cursor has been set during the
 	 redisplay.  Give up if new fonts were loaded.  */
-      if (!try_window (window, startp))
+      val = try_window (window, startp, 1);
+      if (!val)
 	{
 	  w->force_start = Qt;
 	  clear_glyph_matrix (w->desired_matrix);
 	  goto need_larger_matrices;
 	}
+      /* Point was outside the scroll margins.  */
+      if (val < 0)
+	new_vpos = window_box_height (w) / 2;
 
       if (w->cursor.vpos < 0 && !w->frozen_window_start_p)
 	{
@@ -12349,7 +12354,7 @@ redisplay_window (window, just_this_one_p)
 	      && !NILP (current_buffer->mark_active))
 	    {
 	      clear_glyph_matrix (w->desired_matrix);
-	      if (!try_window (window, startp))
+	      if (!try_window (window, startp, 0))
 		goto need_larger_matrices;
 	    }
 	}
@@ -12439,7 +12444,11 @@ redisplay_window (window, just_this_one_p)
 	       = try_window_reusing_current_matrix (w)))
 	{
 	  IF_DEBUG (debug_method_add (w, "1"));
-	  try_window (window, startp);
+	  if (try_window (window, startp, 1) < 0)
+	    /* -1 means we need to scroll.
+	       0 means we need new matrices, but fonts_changed_p
+	       is set in that case, so we will detect it below.  */
+	    goto try_to_scroll;
 	}
 
       if (fonts_changed_p)
@@ -12569,7 +12578,7 @@ redisplay_window (window, just_this_one_p)
       || MINI_WINDOW_P (w)
       || !(used_current_matrix_p
 	   = try_window_reusing_current_matrix (w)))
-    try_window (window, startp);
+    try_window (window, startp, 0);
 
   /* If new fonts have been loaded (due to fontsets), give up.  We
      have to start a new redisplay since we need to re-adjust glyph
@@ -12589,13 +12598,13 @@ redisplay_window (window, just_this_one_p)
 	{
 	  clear_glyph_matrix (w->desired_matrix);
 	  move_it_by_lines (&it, 1, 0);
-	  try_window (window, it.current.pos);
+	  try_window (window, it.current.pos, 0);
 	}
       else if (PT < IT_CHARPOS (it))
 	{
 	  clear_glyph_matrix (w->desired_matrix);
 	  move_it_by_lines (&it, -1, 0);
-	  try_window (window, it.current.pos);
+	  try_window (window, it.current.pos, 0);
 	}
       else
 	{
@@ -12778,14 +12787,18 @@ redisplay_window (window, just_this_one_p)
 
 
 /* Build the complete desired matrix of WINDOW with a window start
-   buffer position POS.  Value is non-zero if successful.  It is zero
-   if fonts were loaded during redisplay which makes re-adjusting
-   glyph matrices necessary.  */
+   buffer position POS.
+
+   Value is 1 if successful.  It is zero if fonts were loaded during
+   redisplay which makes re-adjusting glyph matrices necessary, and -1
+   if point would appear in the scroll margins.
+   (We check that only if CHECK_MARGINS is nonzero.  */
 
 int
-try_window (window, pos)
+try_window (window, pos, check_margins)
      Lisp_Object window;
      struct text_pos pos;
+     int check_margins;
 {
   struct window *w = XWINDOW (window);
   struct it it;
@@ -12810,6 +12823,30 @@ try_window (window, pos)
 	return 0;
     }
 
+  /* Don't let the cursor end in the scroll margins.  */
+  if (check_margins)
+    {
+      int this_scroll_margin, cursor_height;
+
+      this_scroll_margin = max (0, scroll_margin);
+      this_scroll_margin = min (this_scroll_margin, WINDOW_TOTAL_LINES (w) / 4);
+      this_scroll_margin *= FRAME_LINE_HEIGHT (it.f);
+      cursor_height = MATRIX_ROW (w->desired_matrix, w->cursor.vpos)->height;
+
+      if ((w->cursor.y < this_scroll_margin
+	   && CHARPOS (pos) > BEGV)
+	  /* Old redisplay didn't take scroll margin into account at the bottom,
+	     but then global-hl-line-mode doesn't scroll.  KFS 2004-06-14 */
+	  || (w->cursor.y + (make_cursor_line_fully_visible_p
+			     ? cursor_height + this_scroll_margin
+			     : 1)) > it.last_visible_y)
+	{
+	  w->cursor.vpos = -1;
+	  clear_glyph_matrix (w->desired_matrix);
+	  return -1;
+	}
+    }
+
   /* If bottom moved off end of frame, change mode line percentage.  */
   if (XFASTINT (w->window_end_pos) <= 0
       && Z != IT_CHARPOS (it))
@@ -21801,7 +21838,7 @@ note_mouse_highlight (f, x, y)
   /* If we were displaying active text in another window, clear that.
      Also clear if we move out of text area in same window.  */
   if (! EQ (window, dpyinfo->mouse_face_window)
-      || (part != ON_TEXT && part != ON_MODE_LINE && part != ON_HEADER_LINE 
+      || (part != ON_TEXT && part != ON_MODE_LINE && part != ON_HEADER_LINE
 	  && !NILP (dpyinfo->mouse_face_window)))
     clear_mouse_face (dpyinfo);
 
@@ -23026,17 +23063,17 @@ The face used for trailing whitespace is `trailing-whitespace'.  */);
 
   DEFVAR_LISP ("nobreak-char-display", &Vnobreak_char_display,
     doc: /* *Control highlighting of nobreak space and soft hyphen.
-t means highlight the character itself (for nobreak space,
-use face `nobreak-space'.
-nil means no highlighting.
-other values mean display the escape glyph followed by an ordinary
+A value of t means highlight the character itself (for nobreak space,
+use face `nobreak-space').
+A value of nil means no highlighting.
+Other values mean display the escape glyph followed by an ordinary
 space or ordinary hyphen.  */);
   Vnobreak_char_display = Qt;
 
   DEFVAR_LISP ("void-text-area-pointer", &Vvoid_text_area_pointer,
     doc: /* *The pointer shape to show in void text areas.
-Nil means to show the text pointer.  Other options are `arrow', `text',
-`hand', `vdrag', `hdrag', `modeline', and `hourglass'.  */);
+A value of nil means to show the text pointer.  Other options are `arrow',
+`text', `hand', `vdrag', `hdrag', `modeline', and `hourglass'.  */);
   Vvoid_text_area_pointer = Qarrow;
 
   DEFVAR_LISP ("inhibit-redisplay", &Vinhibit_redisplay,
diff --git a/src/xfns.c b/src/xfns.c
index e5efec27b7d..1de6fc71d1a 100644
--- a/src/xfns.c
+++ b/src/xfns.c
@@ -5070,7 +5070,7 @@ Text larger than the specified size is clipped.  */)
   clear_glyph_matrix (w->desired_matrix);
   clear_glyph_matrix (w->current_matrix);
   SET_TEXT_POS (pos, BEGV, BEGV_BYTE);
-  try_window (FRAME_ROOT_WINDOW (f), pos);
+  try_window (FRAME_ROOT_WINDOW (f), pos, 0);
 
   /* Compute width and height of the tooltip.  */
   width = height = 0;