xdisp.c 101 KB
Newer Older
Jim Blandy's avatar
Jim Blandy committed
1
/* Display generation from window structure and buffer text.
2
   Copyright (C) 1985, 86, 87, 88, 93, 94 Free Software Foundation, Inc.
Jim Blandy's avatar
Jim Blandy committed
3 4 5 6 7

This file is part of GNU Emacs.

GNU Emacs is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
8
the Free Software Foundation; either version 2, or (at your option)
Jim Blandy's avatar
Jim Blandy committed
9 10 11 12 13 14 15 16 17 18 19 20
any later version.

GNU Emacs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Emacs; see the file COPYING.  If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */


21
#include <config.h>
Jim Blandy's avatar
Jim Blandy committed
22 23 24 25
#include <stdio.h>
/*#include <ctype.h>*/
#undef NULL
#include "lisp.h"
Jim Blandy's avatar
Jim Blandy committed
26
#include "frame.h"
Jim Blandy's avatar
Jim Blandy committed
27 28 29 30 31 32 33 34
#include "window.h"
#include "termchar.h"
#include "dispextern.h"
#include "buffer.h"
#include "indent.h"
#include "commands.h"
#include "macros.h"
#include "disptab.h"
35
#include "termhooks.h"
36
#include "intervals.h"
Jim Blandy's avatar
Jim Blandy committed
37

38 39 40 41
#ifdef USE_X_TOOLKIT
extern void set_frame_menubar ();
#endif

Jim Blandy's avatar
Jim Blandy committed
42 43 44
extern int interrupt_input;
extern int command_loop_level;

45 46
extern Lisp_Object Qface;

Jim Blandy's avatar
Jim Blandy committed
47 48 49 50 51 52 53 54
/* Nonzero means print newline before next minibuffer message.  */

int noninteractive_need_newline;

#define min(a, b) ((a) < (b) ? (a) : (b))
#define max(a, b) ((a) > (b) ? (a) : (b))

/* The buffer position of the first character appearing
Jim Blandy's avatar
Jim Blandy committed
55 56
 entirely or partially on the current frame line.
 Or zero, which disables the optimization for the current frame line. */
Jim Blandy's avatar
Jim Blandy committed
57 58 59 60 61 62
static int this_line_bufpos;

/* Number of characters past the end of this line,
   including the terminating newline */
static int this_line_endpos;

Jim Blandy's avatar
Jim Blandy committed
63
/* The vertical position of this frame line. */
Jim Blandy's avatar
Jim Blandy committed
64 65
static int this_line_vpos;

Jim Blandy's avatar
Jim Blandy committed
66
/* Hpos value for start of display on this frame line.
Jim Blandy's avatar
Jim Blandy committed
67 68 69 70 71 72 73 74
   Usually zero, but negative if first character really began
   on previous line */
static int this_line_start_hpos;

/* Buffer that this_line variables are describing. */
static struct buffer *this_line_buffer;

/* Set by try_window_id to the vpos of first of any lines
Jim Blandy's avatar
Jim Blandy committed
75
   scrolled on to the bottom of the frame.  These lines should
Jim Blandy's avatar
Jim Blandy committed
76 77 78 79
   not be included in any general scroll computation.  */
static int scroll_bottom_vpos;

/* Value of echo_area_glyphs when it was last acted on.
Jim Blandy's avatar
Jim Blandy committed
80
  If this is nonzero, there is a message on the frame
Jim Blandy's avatar
Jim Blandy committed
81 82 83 84
  in the minibuffer and it should be erased as soon
  as it is no longer requested to appear. */
char *previous_echo_glyphs;

Jim Blandy's avatar
Jim Blandy committed
85
/* Nonzero means truncate lines in all windows less wide than the frame */
Jim Blandy's avatar
Jim Blandy committed
86 87 88 89 90 91 92 93 94 95 96
int truncate_partial_width_windows;

Lisp_Object Vglobal_mode_string;

/* Marker for where to display an arrow on top of the buffer text.  */
Lisp_Object Voverlay_arrow_position;

/* String to display for the arrow.  */
Lisp_Object Voverlay_arrow_string;

/* Values of those variables at last redisplay.  */
97
static Lisp_Object last_arrow_position, last_arrow_string;
Jim Blandy's avatar
Jim Blandy committed
98

99 100
Lisp_Object Qmenu_bar_update_hook;

Jim Blandy's avatar
Jim Blandy committed
101 102 103
/* Nonzero if overlay arrow has been displayed once in this window.  */
static int overlay_arrow_seen;

104 105 106
/* Nonzero means highlight the region even in nonselected windows.  */
static int highlight_nonselected_windows;

Jim Blandy's avatar
Jim Blandy committed
107
/* If cursor motion alone moves point off frame,
Jim Blandy's avatar
Jim Blandy committed
108 109 110 111 112 113 114 115 116 117 118
   Try scrolling this many lines up or down if that will bring it back.  */
int scroll_step;

/* Nonzero if try_window_id has made blank lines at window bottom
 since the last redisplay that paused */
static int blank_end_of_window;

/* Number of windows showing the buffer of the selected window.
   keyboard.c refers to this.  */
int buffer_shared;

Jim Blandy's avatar
Jim Blandy committed
119
/* display_text_line sets these to the frame position (origin 0) of point,
Jim Blandy's avatar
Jim Blandy committed
120 121 122 123 124 125 126 127 128 129 130 131 132 133 134
   whether the window is selected or not.
   Set one to -1 first to determine whether point was found afterwards.  */

static int cursor_vpos;
static int cursor_hpos;

int debug_end_pos;

/* Nonzero means display mode line highlighted */
int mode_line_inverse_video;

static void echo_area_display ();
void mark_window_display_accurate ();
static void redisplay_windows ();
static void redisplay_window ();
135 136
static void update_menu_bars ();
static void update_menu_bar ();
Jim Blandy's avatar
Jim Blandy committed
137 138 139 140 141 142 143 144
static void try_window ();
static int try_window_id ();
static struct position *display_text_line ();
static void display_mode_line ();
static int display_mode_element ();
static char *fmodetrunc ();
static char *decode_mode_spec ();
static int display_string ();
145
static void display_menu_bar ();
146
static int display_count_lines ();
Jim Blandy's avatar
Jim Blandy committed
147 148

/* Prompt to display in front of the minibuffer contents */
149
Lisp_Object minibuf_prompt;
Jim Blandy's avatar
Jim Blandy committed
150 151 152 153 154 155 156 157 158 159

/* Width in columns of current minibuffer prompt.  */
int minibuf_prompt_width;

/* Message to display instead of minibuffer contents
   This is what the functions error and message make,
   and command echoing uses it as well.
   It overrides the minibuf_prompt as well as the buffer.  */
char *echo_area_glyphs;

160 161 162
/* This is the length of the message in echo_area_glyphs.  */
int echo_area_glyphs_length;

Jim Blandy's avatar
Jim Blandy committed
163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188
/* true iff we should redraw the mode lines on the next redisplay */
int update_mode_lines;

/* Smallest number of characters before the gap
   at any time since last redisplay that finished.
   Valid for current buffer when try_window_id can be called.  */
int beg_unchanged;

/* Smallest number of characters after the gap
   at any time since last redisplay that finished.
   Valid for current buffer when try_window_id can be called.  */
int end_unchanged;

/* MODIFF as of last redisplay that finished;
   if it matches MODIFF, beg_unchanged and end_unchanged
   contain no useful information */
int unchanged_modified;

/* Nonzero if head_clip or tail_clip of current buffer has changed
   since last redisplay that finished */
int clip_changed;

/* Nonzero if window sizes or contents have changed
   since last redisplay that finished */
int windows_or_buffers_changed;

189 190 191 192 193 194
/* Nonzero after display_mode_line if %l was used
   and it displayed a line number.  */
int line_number_displayed;

/* Maximum buffer size for which to display line numbers.  */
int line_number_display_limit;
Jim Blandy's avatar
Jim Blandy committed
195

196
/* Display an echo area message M with a specified length of LEN chars.
197 198 199
   The string may include null characters.  If m is 0, clear out any
   existing message, and let the minibuffer text show through.
   Do not pass text that is stored in a Lisp string.  */
200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236

void
message2 (m, len)
     char *m;
     int len;
{
  if (noninteractive)
    {
      if (noninteractive_need_newline)
	putc ('\n', stderr);
      noninteractive_need_newline = 0;
      fwrite (m, len, 1, stderr);
      if (cursor_in_echo_area == 0)
	fprintf (stderr, "\n");
      fflush (stderr);
    }
  /* A null message buffer means that the frame hasn't really been
     initialized yet.  Error messages get reported properly by
     cmd_error, so this must be just an informative message; toss it.  */
  else if (INTERACTIVE && FRAME_MESSAGE_BUF (selected_frame))
    {
#ifdef MULTI_FRAME
      Lisp_Object minibuf_frame;

      choose_minibuf_frame ();
      minibuf_frame = WINDOW_FRAME (XWINDOW (minibuf_window));
      FRAME_SAMPLE_VISIBILITY (XFRAME (minibuf_frame));
      if (FRAME_VISIBLE_P (selected_frame)
	  && ! FRAME_VISIBLE_P (XFRAME (minibuf_frame)))
	Fmake_frame_visible (WINDOW_FRAME (XWINDOW (minibuf_window)));
#endif

      if (m)
	{
	  echo_area_glyphs = m;
	  echo_area_glyphs_length = len;
	}
237 238 239 240 241 242 243
      else
	echo_area_glyphs = previous_echo_glyphs = 0;

      do_pending_window_change ();
      echo_area_display ();
      update_frame (XFRAME (XWINDOW (minibuf_window)->frame), 1, 1);
      do_pending_window_change ();
244 245
      if (frame_up_to_date_hook != 0 && ! gc_in_progress)
	(*frame_up_to_date_hook) (XFRAME (XWINDOW (minibuf_window)->frame));
246 247 248
    }
}

249 250 251 252 253 254 255
void
message1 (m)
     char *m;
{
  message2 (m, (m ? strlen (m) : 0));
}

256 257 258 259 260 261 262 263 264 265 266 267 268 269
/* Truncate what will be displayed in the echo area
   the next time we display it--but don't redisplay it now.  */

void
truncate_echo_area (len)
     int len;
{
  /* A null message buffer means that the frame hasn't really been
     initialized yet.  Error messages get reported properly by
     cmd_error, so this must be just an informative message; toss it.  */
  if (!noninteractive && INTERACTIVE && FRAME_MESSAGE_BUF (selected_frame))
    echo_area_glyphs_length = len;
}

Jim Blandy's avatar
Jim Blandy committed
270
/* Nonzero if FRAME_MESSAGE_BUF (selected_frame) is being used by print;
Jim Blandy's avatar
Jim Blandy committed
271 272 273
   zero if being used by message.  */
int message_buf_print;

274 275
/* Dump an informative message to the minibuf.  If m is 0, clear out
   any existing message, and let the minibuffer text show through.  */
Jim Blandy's avatar
Jim Blandy committed
276 277 278 279 280 281 282
/* VARARGS 1 */
void
message (m, a1, a2, a3)
     char *m;
{
  if (noninteractive)
    {
283 284 285 286 287 288
      if (m)
	{
	  if (noninteractive_need_newline)
	    putc ('\n', stderr);
	  noninteractive_need_newline = 0;
	  fprintf (stderr, m, a1, a2, a3);
289 290
	  if (cursor_in_echo_area == 0)
	    fprintf (stderr, "\n");
291 292
	  fflush (stderr);
	}
Jim Blandy's avatar
Jim Blandy committed
293
    }
294
  else if (INTERACTIVE)
Jim Blandy's avatar
Jim Blandy committed
295
    {
296 297 298 299 300 301 302 303 304 305 306 307 308 309 310
      /* The frame whose minibuffer we're going to display the message on.
	 It may be larger than the selected frame, so we need
	 to use its buffer, not the selected frame's buffer.  */
      FRAME_PTR echo_frame;
#ifdef MULTI_FRAME
      choose_minibuf_frame ();
      echo_frame = XFRAME (WINDOW_FRAME (XWINDOW (minibuf_window)));
#else
      echo_frame = selected_frame;
#endif

      /* A null message buffer means that the frame hasn't really been
	 initialized yet.  Error messages get reported properly by
	 cmd_error, so this must be just an informative message; toss it.  */
      if (FRAME_MESSAGE_BUF (echo_frame))
311
	{
312 313
	  if (m)
	    {
314
	      int len;
Jim Blandy's avatar
Jim Blandy committed
315
#ifdef NO_ARG_ARRAY
316 317 318 319
	      int a[3];
	      a[0] = a1;
	      a[1] = a2;
	      a[2] = a3;
Jim Blandy's avatar
Jim Blandy committed
320

321 322
	      len = doprnt (FRAME_MESSAGE_BUF (echo_frame),
			    FRAME_WIDTH (echo_frame), m, 0, 3, a);
Jim Blandy's avatar
Jim Blandy committed
323
#else
324 325
	      len = doprnt (FRAME_MESSAGE_BUF (echo_frame),
			    FRAME_WIDTH (echo_frame), m, 0, 3, &a1);
326 327
#endif /* NO_ARG_ARRAY */

328
	      message2 (FRAME_MESSAGE_BUF (echo_frame), len);
329 330 331 332 333 334 335
	    }
	  else
	    message1 (0);

	  /* Print should start at the beginning of the message
	     buffer next time.  */
	  message_buf_print = 0;
336
	}
Jim Blandy's avatar
Jim Blandy committed
337 338 339 340 341 342 343
    }
}

static void
echo_area_display ()
{
  register int vpos;
Jim Blandy's avatar
Jim Blandy committed
344
  FRAME_PTR f;
Jim Blandy's avatar
Jim Blandy committed
345

Jim Blandy's avatar
Jim Blandy committed
346 347
#ifdef MULTI_FRAME
  choose_minibuf_frame ();
348 349
#endif

Jim Blandy's avatar
Jim Blandy committed
350
  f = XFRAME (WINDOW_FRAME (XWINDOW (minibuf_window)));
Jim Blandy's avatar
Jim Blandy committed
351

Jim Blandy's avatar
Jim Blandy committed
352
  if (! FRAME_VISIBLE_P (f))
Jim Blandy's avatar
Jim Blandy committed
353 354
    return;

Jim Blandy's avatar
Jim Blandy committed
355
  if (frame_garbaged)
Jim Blandy's avatar
Jim Blandy committed
356
    {
357
      redraw_garbaged_frames ();
Jim Blandy's avatar
Jim Blandy committed
358
      frame_garbaged = 0;
Jim Blandy's avatar
Jim Blandy committed
359 360 361 362 363
    }

  if (echo_area_glyphs || minibuf_level == 0)
    {
      vpos = XFASTINT (XWINDOW (minibuf_window)->top);
Jim Blandy's avatar
Jim Blandy committed
364
      get_display_line (f, vpos, 0);
Jim Blandy's avatar
Jim Blandy committed
365 366
      display_string (XWINDOW (minibuf_window), vpos,
		      echo_area_glyphs ? echo_area_glyphs : "",
367
		      echo_area_glyphs ? echo_area_glyphs_length : -1,
368
		      0, 0, 0, 0, FRAME_WIDTH (f));
Jim Blandy's avatar
Jim Blandy committed
369 370

      /* If desired cursor location is on this line, put it at end of text */
Jim Blandy's avatar
Jim Blandy committed
371 372
      if (FRAME_CURSOR_Y (f) == vpos)
	FRAME_CURSOR_X (f) = FRAME_DESIRED_GLYPHS (f)->used[vpos];
Jim Blandy's avatar
Jim Blandy committed
373 374 375 376 377

      /* Fill the rest of the minibuffer window with blank lines.  */
      {
	int i;

378 379
	for (i = vpos + 1;
	     i < vpos + XFASTINT (XWINDOW (minibuf_window)->height); i++)
Jim Blandy's avatar
Jim Blandy committed
380
	  {
Jim Blandy's avatar
Jim Blandy committed
381
	    get_display_line (f, i, 0);
Jim Blandy's avatar
Jim Blandy committed
382
	    display_string (XWINDOW (minibuf_window), vpos,
383
			    "", 0, 0, 0, 0, 0, FRAME_WIDTH (f));
Jim Blandy's avatar
Jim Blandy committed
384 385
	  }
      }
Jim Blandy's avatar
Jim Blandy committed
386 387 388 389 390 391 392 393 394
    }
  else if (!EQ (minibuf_window, selected_window))
    windows_or_buffers_changed++;

  if (EQ (minibuf_window, selected_window))
    this_line_bufpos = 0;

  previous_echo_glyphs = echo_area_glyphs;
}
395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413

#ifdef HAVE_X_WINDOWS
/* I'm trying this out because I saw Unimpress use it, but it's
   possible that this may mess adversely with some window managers.  -jla

   Wouldn't it be nice to use something like mode-line-format to
   describe frame titles?  -JimB  */

/* Change the title of the frame to the name of the buffer displayed
   in the currently selected window.  Don't do this for minibuffer frames,
   and don't do it when there's only one non-minibuffer frame.  */
static void
x_consider_frame_title (frame)
     Lisp_Object frame;
{
  FRAME_PTR f = XFRAME (frame);

  if (FRAME_X_P (f) && ! FRAME_MINIBUF_ONLY_P (f))
    {
414
      Lisp_Object title;
415

416
      title = Qnil;
417 418 419 420 421 422 423
      if (! EQ (Fnext_frame (frame, Qnil), frame))
	title = XBUFFER (XWINDOW (f->selected_window)->buffer)->name;

      x_implicitly_set_name (f, title, Qnil);
    }
}
#endif
Jim Blandy's avatar
Jim Blandy committed
424

425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456
/* Prepare for redisplay by updating menu-bar item lists when appropriate.
   This can't be done in `redisplay' itself because it can call eval.  */

void
prepare_menu_bars ()
{
  register struct window *w = XWINDOW (selected_window);
  int all_windows;

  if (noninteractive)
    return;

  /* Set the visible flags for all frames.
     Do this before checking for resized or garbaged frames; they want
     to know if their frames are visible.
     See the comment in frame.h for FRAME_SAMPLE_VISIBILITY.  */
  {
    Lisp_Object tail, frame;

    FOR_EACH_FRAME (tail, frame)
      FRAME_SAMPLE_VISIBILITY (XFRAME (frame));
  }

  /* Notice any pending interrupt request to change frame size.  */
  do_pending_window_change ();

  if (frame_garbaged)
    {
      redraw_garbaged_frames ();
      frame_garbaged = 0;
    }

457 458
  all_windows = (update_mode_lines || buffer_shared > 1
		 || clip_changed || windows_or_buffers_changed);
459

460
#ifdef HAVE_X_WINDOWS
461 462 463
  if (windows_or_buffers_changed)
    {
      Lisp_Object tail, frame;
464

465 466 467 468 469
      FOR_EACH_FRAME (tail, frame)
	if (FRAME_VISIBLE_P (XFRAME (frame))
	    || FRAME_ICONIFIED_P (XFRAME (frame)))
	  x_consider_frame_title (frame);
    }
470 471
#endif

472 473 474 475 476 477 478 479
  /* Update the menu bar item lists, if appropriate.
     This has to be done before any actual redisplay
     or generation of display lines.  */
  if (all_windows)
    {
      Lisp_Object tail, frame;

      FOR_EACH_FRAME (tail, frame)
480
	update_menu_bar (XFRAME (frame));
481
    }
482 483
  else
    update_menu_bar (selected_frame);
484 485
}

Jim Blandy's avatar
Jim Blandy committed
486
/* Do a frame update, taking possible shortcuts into account.
Jim Blandy's avatar
Jim Blandy committed
487 488 489 490 491 492
   This is the main external entry point for redisplay.

   If the last redisplay displayed an echo area message and that
   message is no longer requested, we clear the echo area
   or bring back the minibuffer if that is in use.

493 494 495 496 497 498
   Do not call eval from within this function.
   Calls to eval after the call to echo_area_display would confuse
   the display_line mechanism and would cause a crash.
   Calls to eval before that point will work most of the time,
   but can still lose, because  this function
   can be called from signal handlers; with alarms set up;
Jim Blandy's avatar
Jim Blandy committed
499
   or with synchronous processes running.
500

Jim Blandy's avatar
Jim Blandy committed
501 502 503
   See Fcall_process; if you called it from here, it could be
   entered recursively.  */

504 505
static int do_verify_charstarts;

Jim Blandy's avatar
Jim Blandy committed
506 507 508 509 510 511 512 513 514 515 516 517 518 519
void
redisplay ()
{
  register struct window *w = XWINDOW (selected_window);
  register int pause;
  int must_finish = 0;
  int all_windows;
  register int tlbufpos, tlendpos;
  struct position pos;
  extern int input_pending;

  if (noninteractive)
    return;

520 521 522 523 524
  /* Set the visible flags for all frames.
     Do this before checking for resized or garbaged frames; they want
     to know if their frames are visible.
     See the comment in frame.h for FRAME_SAMPLE_VISIBILITY.  */
  {
525
    Lisp_Object tail, frame;
526

527 528
    FOR_EACH_FRAME (tail, frame)
      FRAME_SAMPLE_VISIBILITY (XFRAME (frame));
529 530
  }

Jim Blandy's avatar
Jim Blandy committed
531
  /* Notice any pending interrupt request to change frame size.  */
Jim Blandy's avatar
Jim Blandy committed
532 533
  do_pending_window_change ();

Jim Blandy's avatar
Jim Blandy committed
534
  if (frame_garbaged)
Jim Blandy's avatar
Jim Blandy committed
535
    {
536
      redraw_garbaged_frames ();
Jim Blandy's avatar
Jim Blandy committed
537
      frame_garbaged = 0;
Jim Blandy's avatar
Jim Blandy committed
538 539 540 541 542 543 544 545 546 547 548 549 550 551
    }

  if (clip_changed || windows_or_buffers_changed)
    update_mode_lines++;

  /* Detect case that we need to write a star in the mode line.  */
  if (XFASTINT (w->last_modified) < MODIFF
      && XFASTINT (w->last_modified) <= current_buffer->save_modified)
    {
      w->update_mode_line = Qt;
      if (buffer_shared > 1)
	update_mode_lines++;
    }

Jim Blandy's avatar
Jim Blandy committed
552
  FRAME_SCROLL_BOTTOM_VPOS (XFRAME (w->frame)) = -1;
Jim Blandy's avatar
Jim Blandy committed
553 554 555 556 557

  all_windows = update_mode_lines || buffer_shared > 1;

  /* If specs for an arrow have changed, do thorough redisplay
     to ensure we remove any arrow that should no longer exist.  */
558 559
  if (! EQ (Voverlay_arrow_position, last_arrow_position)
      || ! EQ (Voverlay_arrow_string, last_arrow_string))
Jim Blandy's avatar
Jim Blandy committed
560 561
    all_windows = 1, clip_changed = 1;

562 563 564 565 566 567 568 569 570 571
  /* Normally the message* functions will have already displayed and
     updated the echo area, but the frame may have been trashed, or
     the update may have been preempted, so display the echo area
     again here.  */
  if (echo_area_glyphs || previous_echo_glyphs)
    {
      echo_area_display ();
      must_finish = 1;
    }

572 573 574 575
  /* If showing region, and mark has changed, must redisplay whole window.  */
  if (((!NILP (Vtransient_mark_mode)
	&& !NILP (XBUFFER (w->buffer)->mark_active))
       != !NILP (w->region_showing))
576 577 578
      || (!NILP (w->region_showing)
	  && !EQ (w->region_showing,
		  Fmarker_position (XBUFFER (w->buffer)->mark))))
579 580
    this_line_bufpos = -1;

Jim Blandy's avatar
Jim Blandy committed
581 582
  tlbufpos = this_line_bufpos;
  tlendpos = this_line_endpos;
Jim Blandy's avatar
Jim Blandy committed
583
  if (!all_windows && tlbufpos > 0 && NILP (w->update_mode_line)
Jim Blandy's avatar
Jim Blandy committed
584
      && FRAME_VISIBLE_P (XFRAME (w->frame))
Jim Blandy's avatar
Jim Blandy committed
585 586 587
      /* Make sure recorded data applies to current buffer, etc */
      && this_line_buffer == current_buffer
      && current_buffer == XBUFFER (w->buffer)
Jim Blandy's avatar
Jim Blandy committed
588
      && NILP (w->force_start)
Jim Blandy's avatar
Jim Blandy committed
589
      /* Point must be on the line that we have info recorded about */
Karl Heuer's avatar
Karl Heuer committed
590 591
      && PT >= tlbufpos
      && PT <= Z - tlendpos
Jim Blandy's avatar
Jim Blandy committed
592 593 594 595 596
      /* All text outside that line, including its final newline,
	 must be unchanged */
      && (XFASTINT (w->last_modified) >= MODIFF
	  || (beg_unchanged >= tlbufpos - 1
	      && GPT >= tlbufpos
Jim Blandy's avatar
Jim Blandy committed
597 598 599 600 601 602 603
	      /* If selective display, can't optimize
		 if the changes start at the beginning of the line.  */
	      && ((XTYPE (current_buffer->selective_display) == Lisp_Int
		   && XINT (current_buffer->selective_display) > 0
		   ? (beg_unchanged >= tlbufpos
		      && GPT > tlbufpos)
		   : 1))
Jim Blandy's avatar
Jim Blandy committed
604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623
	      && end_unchanged >= tlendpos
	      && Z - GPT >= tlendpos)))
    {
      if (tlbufpos > BEGV && FETCH_CHAR (tlbufpos - 1) != '\n'
	  && (tlbufpos == ZV
	      || FETCH_CHAR (tlbufpos) == '\n'))
	/* Former continuation line has disappeared by becoming empty */
	goto cancel;
      else if (XFASTINT (w->last_modified) < MODIFF
	       || MINI_WINDOW_P (w))
	{
	  cursor_vpos = -1;
	  overlay_arrow_seen = 0;
	  display_text_line (w, tlbufpos, this_line_vpos, this_line_start_hpos,
			     pos_tab_offset (w, tlbufpos));
	  /* If line contains point, is not continued,
		 and ends at same distance from eob as before, we win */
	  if (cursor_vpos >= 0 && this_line_bufpos
	      && this_line_endpos == tlendpos)
	    {
624 625 626 627
	      /* If this is not the window's last line,
		 we must adjust the charstarts of the lines below.  */
	      if (this_line_vpos + 1
		  < XFASTINT (w->top) + window_internal_height (w))
628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646
		{
		  int left = XFASTINT (w->left);
		  int *charstart_next_line
		    = FRAME_CURRENT_GLYPHS (XFRAME (WINDOW_FRAME (w)))->charstarts[this_line_vpos + 1];
		  int i;
		  int adjust;

		  if (Z - tlendpos == ZV)
		    /* This line ends at end of (accessible part of) buffer.
		       There is no newline to count.  */
		    adjust = Z - tlendpos - charstart_next_line[left];
		  else
		    /* This line ends in a newline.
		       Must take account of the newline and the rest of the
		       text that follows.  */
		    adjust = Z - tlendpos + 1 - charstart_next_line[left];

		  adjust_window_charstarts (w, this_line_vpos, adjust);
		}
647

Jim Blandy's avatar
Jim Blandy committed
648
	      if (XFASTINT (w->width) != FRAME_WIDTH (XFRAME (WINDOW_FRAME (w))))
Jim Blandy's avatar
Jim Blandy committed
649 650 651 652 653 654
		preserve_other_columns (w);
	      goto update;
	    }
	  else
	    goto cancel;
	}
Karl Heuer's avatar
Karl Heuer committed
655
      else if (PT == XFASTINT (w->last_point))
Jim Blandy's avatar
Jim Blandy committed
656 657 658 659 660 661 662 663
	{
	  if (!must_finish)
	    {
	      do_pending_window_change ();
	      return;
	    }
	  goto update;
	}
664 665 666 667
      /* If highlighting the region, we can't just move the cursor.  */
      else if (! (!NILP (Vtransient_mark_mode)
		  && !NILP (current_buffer->mark_active))
	       && NILP (w->region_showing))
Jim Blandy's avatar
Jim Blandy committed
668 669 670
	{
	  pos = *compute_motion (tlbufpos, 0,
				 XINT (w->hscroll) ? 1 - XINT (w->hscroll) : 0,
Karl Heuer's avatar
Karl Heuer committed
671
				 PT, 2, - (1 << (SHORTBITS - 1)),
672
				 window_internal_width (w) - 1,
Jim Blandy's avatar
Jim Blandy committed
673
				 XINT (w->hscroll),
674
				 pos_tab_offset (w, tlbufpos), w);
Jim Blandy's avatar
Jim Blandy committed
675 676
	  if (pos.vpos < 1)
	    {
Jim Blandy's avatar
Jim Blandy committed
677
	      FRAME_CURSOR_X (selected_frame)
Jim Blandy's avatar
Jim Blandy committed
678
		= XFASTINT (w->left) + max (pos.hpos, 0);
Jim Blandy's avatar
Jim Blandy committed
679
	      FRAME_CURSOR_Y (selected_frame) = this_line_vpos;
Jim Blandy's avatar
Jim Blandy committed
680 681 682 683 684 685 686
	      goto update;
	    }
	  else
	    goto cancel;
	}
    cancel:
      /* Text changed drastically or point moved off of line */
Jim Blandy's avatar
Jim Blandy committed
687
      cancel_line (this_line_vpos, selected_frame);
Jim Blandy's avatar
Jim Blandy committed
688 689 690 691 692 693 694
    }

  this_line_bufpos = 0;
  all_windows |= buffer_shared > 1;

  if (all_windows)
    {
695
      Lisp_Object tail, frame;
Jim Blandy's avatar
Jim Blandy committed
696

697 698 699 700 701 702
#ifdef HAVE_X_WINDOWS
      /* Since we're doing a thorough redisplay, we might as well
	 recompute all our display faces.  */
      clear_face_vector ();
#endif

Jim Blandy's avatar
Jim Blandy committed
703
      /* Recompute # windows showing selected buffer.
Jim Blandy's avatar
Jim Blandy committed
704
	 This will be incremented each time such a window is displayed.  */
Jim Blandy's avatar
Jim Blandy committed
705 706
      buffer_shared = 0;

707
      FOR_EACH_FRAME (tail, frame)
708
	{
709 710
	  FRAME_PTR f = XFRAME (frame);

711
	  /* Mark all the scroll bars to be removed; we'll redeem the ones
712
	     we want when we redisplay their windows.  */
713 714
	  if (condemn_scroll_bars_hook)
	    (*condemn_scroll_bars_hook) (f);
715 716 717 718

	  if (FRAME_VISIBLE_P (f))
	    redisplay_windows (FRAME_ROOT_WINDOW (f));

719
	  /* Any scroll bars which redisplay_windows should have nuked
720
	     should now go away.  */
721 722
	  if (judge_scroll_bars_hook)
	    (*judge_scroll_bars_hook) (f);
723
	}
Jim Blandy's avatar
Jim Blandy committed
724
    }
Jim Blandy's avatar
Jim Blandy committed
725
  else if (FRAME_VISIBLE_P (selected_frame))
Jim Blandy's avatar
Jim Blandy committed
726 727
    {
      redisplay_window (selected_window, 1);
Jim Blandy's avatar
Jim Blandy committed
728
      if (XFASTINT (w->width) != FRAME_WIDTH (selected_frame))
Jim Blandy's avatar
Jim Blandy committed
729 730 731 732 733 734 735 736 737 738 739
	preserve_other_columns (w);
    }

update: 
  /* Prevent various kinds of signals during display update.
     stdio is not robust about handling signals,
     which can cause an apparent I/O error.  */
  if (interrupt_input)
    unrequest_sigio ();
  stop_polling ();

Jim Blandy's avatar
Jim Blandy committed
740
#ifdef MULTI_FRAME
Jim Blandy's avatar
Jim Blandy committed
741 742 743 744 745 746
  if (all_windows)
    {
      Lisp_Object tail;

      pause = 0;

Jim Blandy's avatar
Jim Blandy committed
747
      for (tail = Vframe_list; CONSP (tail); tail = XCONS (tail)->cdr)
Jim Blandy's avatar
Jim Blandy committed
748
	{
Jim Blandy's avatar
Jim Blandy committed
749
	  FRAME_PTR f;
Jim Blandy's avatar
Jim Blandy committed
750

Jim Blandy's avatar
Jim Blandy committed
751
	  if (XTYPE (XCONS (tail)->car) != Lisp_Frame)
Jim Blandy's avatar
Jim Blandy committed
752 753
	    continue;

Jim Blandy's avatar
Jim Blandy committed
754
	  f = XFRAME (XCONS (tail)->car);
755
	  if (FRAME_VISIBLE_P (f))
Jim Blandy's avatar
Jim Blandy committed
756
	    {
Jim Blandy's avatar
Jim Blandy committed
757
	      pause |= update_frame (f, 0, 0);
Jim Blandy's avatar
Jim Blandy committed
758
	      if (!pause)
759 760 761 762 763
		{
		  mark_window_display_accurate (f->root_window, 1);
		  if (frame_up_to_date_hook != 0)
		    (*frame_up_to_date_hook) (f);
		}
Jim Blandy's avatar
Jim Blandy committed
764 765 766 767
	    }
	}
    }
  else
Jim Blandy's avatar
Jim Blandy committed
768
#endif /* MULTI_FRAME */
Jim Blandy's avatar
Jim Blandy committed
769
    {
Jim Blandy's avatar
Jim Blandy committed
770 771
      if (FRAME_VISIBLE_P (selected_frame))
	pause = update_frame (selected_frame, 0, 0);
772

Jim Blandy's avatar
Jim Blandy committed
773
      /* We may have called echo_area_display at the top of this
Jim Blandy's avatar
Jim Blandy committed
774 775 776
	 function.  If the echo area is on another frame, that may
	 have put text on a frame other than the selected one, so the
	 above call to update_frame would not have caught it.  Catch
Jim Blandy's avatar
Jim Blandy committed
777 778
	 it here.  */
      {
779 780
	FRAME_PTR mini_frame
	  = XFRAME (WINDOW_FRAME (XWINDOW (minibuf_window)));
Jim Blandy's avatar
Jim Blandy committed
781
	
Jim Blandy's avatar
Jim Blandy committed
782 783
	if (mini_frame != selected_frame)
	  pause |= update_frame (mini_frame, 0, 0);
Jim Blandy's avatar
Jim Blandy committed
784
      }
Jim Blandy's avatar
Jim Blandy committed
785
    }
Jim Blandy's avatar
Jim Blandy committed
786

Jim Blandy's avatar
Jim Blandy committed
787
  /* If frame does not match, prevent doing single-line-update next time.
Jim Blandy's avatar
Jim Blandy committed
788 789 790 791
     Also, don't forget to check every line to update the arrow.  */
  if (pause)
    {
      this_line_bufpos = 0;
Jim Blandy's avatar
Jim Blandy committed
792
      if (!NILP (last_arrow_position))
Jim Blandy's avatar
Jim Blandy committed
793 794 795 796
	{
	  last_arrow_position = Qt;
	  last_arrow_string = Qt;
	}
Jim Blandy's avatar
Jim Blandy committed
797
      /* If we pause after scrolling, some lines in current_frame
Jim Blandy's avatar
Jim Blandy committed
798 799 800
	 may be null, so preserve_other_columns won't be able to
	 preserve all the vertical-bar separators.  So, avoid using it
	 in that case.  */
Jim Blandy's avatar
Jim Blandy committed
801
      if (XFASTINT (w->width) != FRAME_WIDTH (selected_frame))
Jim Blandy's avatar
Jim Blandy committed
802 803 804
	update_mode_lines = 1;
    }

Jim Blandy's avatar
Jim Blandy committed
805
  /* Now text on frame agrees with windows, so
Jim Blandy's avatar
Jim Blandy committed
806 807 808 809 810 811 812 813 814 815 816 817 818
     put info into the windows for partial redisplay to follow */

  if (!pause)
    {
      register struct buffer *b = XBUFFER (w->buffer);

      blank_end_of_window = 0;
      clip_changed = 0;
      unchanged_modified = BUF_MODIFF (b);
      beg_unchanged = BUF_GPT (b) - BUF_BEG (b);
      end_unchanged = BUF_Z (b) - BUF_GPT (b);

      XFASTINT (w->last_point) = BUF_PT (b);
Jim Blandy's avatar
Jim Blandy committed
819 820
      XFASTINT (w->last_point_x) = FRAME_CURSOR_X (selected_frame);
      XFASTINT (w->last_point_y) = FRAME_CURSOR_Y (selected_frame);
Jim Blandy's avatar
Jim Blandy committed
821 822

      if (all_windows)
823
	mark_window_display_accurate (FRAME_ROOT_WINDOW (selected_frame), 1);
Jim Blandy's avatar
Jim Blandy committed
824 825 826 827
      else
	{
	  w->update_mode_line = Qnil;
	  XFASTINT (w->last_modified) = BUF_MODIFF (b);
828
	  w->window_end_valid = w->buffer;
Jim Blandy's avatar
Jim Blandy committed
829 830
	  last_arrow_position = Voverlay_arrow_position;
	  last_arrow_string = Voverlay_arrow_string;
831 832
	  if (do_verify_charstarts)
	    verify_charstarts (w);
833 834
	  if (frame_up_to_date_hook != 0)
	    (*frame_up_to_date_hook) (selected_frame);
Jim Blandy's avatar
Jim Blandy committed
835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850
	}
      update_mode_lines = 0;
      windows_or_buffers_changed = 0;
    }

  /* Start SIGIO interrupts coming again.
     Having them off during the code above
     makes it less likely one will discard output,
     but not impossible, since there might be stuff
     in the system buffer here.
     But it is much hairier to try to do anything about that.  */

  if (interrupt_input)
    request_sigio ();
  start_polling ();

Jim Blandy's avatar
Jim Blandy committed
851
  /* Change frame size now if a change is pending.  */
Jim Blandy's avatar
Jim Blandy committed
852
  do_pending_window_change ();
853 854 855

  /* If we just did a pending size change, redisplay again
     for the new size.  */
856
  if (windows_or_buffers_changed && !pause)
857
    redisplay ();
Jim Blandy's avatar
Jim Blandy committed
858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886
}

/* Redisplay, but leave alone any recent echo area message
   unless another message has been requested in its place.

   This is useful in situations where you need to redisplay but no
   user action has occurred, making it inappropriate for the message
   area to be cleared.  See tracking_off and
   wait_reading_process_input for examples of these situations.  */

redisplay_preserve_echo_area ()
{
  if (echo_area_glyphs == 0 && previous_echo_glyphs != 0)
    {
      echo_area_glyphs = previous_echo_glyphs;
      redisplay ();
      echo_area_glyphs = 0;
    }
  else
    redisplay ();
}

void
mark_window_display_accurate (window, flag)
     Lisp_Object window;
     int flag;
{
  register struct window *w;

Jim Blandy's avatar
Jim Blandy committed
887
  for (;!NILP (window); window = w->next)
Jim Blandy's avatar
Jim Blandy committed
888
    {
889
      if (XTYPE (window) != Lisp_Window) abort ();
Jim Blandy's avatar
Jim Blandy committed
890 891
      w = XWINDOW (window);

Jim Blandy's avatar
Jim Blandy committed
892
      if (!NILP (w->buffer))
893 894 895 896 897 898 899 900 901 902 903 904 905 906
	{
	  XFASTINT (w->last_modified)
	    = !flag ? 0
	      : XBUFFER (w->buffer) == current_buffer
		? MODIFF : BUF_MODIFF (XBUFFER (w->buffer));

	  /* Record if we are showing a region, so can make sure to
	     update it fully at next redisplay.  */
	  w->region_showing = (!NILP (Vtransient_mark_mode)
			       && !NILP (XBUFFER (w->buffer)->mark_active)
			       ? Fmarker_position (XBUFFER (w->buffer)->mark)
			       : Qnil);
	}

907
      w->window_end_valid = w->buffer;
Jim Blandy's avatar
Jim Blandy committed
908 909
      w->update_mode_line = Qnil;

Jim Blandy's avatar
Jim Blandy committed
910
      if (!NILP (w->vchild))
Jim Blandy's avatar
Jim Blandy committed
911
	mark_window_display_accurate (w->vchild, flag);
Jim Blandy's avatar
Jim Blandy committed
912
      if (!NILP (w->hchild))
Jim Blandy's avatar
Jim Blandy committed
913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928
	mark_window_display_accurate (w->hchild, flag);
    }

  if (flag)
    {
      last_arrow_position = Voverlay_arrow_position;
      last_arrow_string = Voverlay_arrow_string;
    }
  else
    {
      /* t is unequal to any useful value of Voverlay_arrow_... */
      last_arrow_position = Qt;
      last_arrow_string = Qt;
    }
}

929
/* Update the menu bar item list for frame F.
930 931 932 933
   This has to be done before we start to fill in any display lines,
   because it can call eval.  */

static void
934 935
update_menu_bar (f)
     FRAME_PTR f;
936 937
{
  struct buffer *old = current_buffer;
938 939 940 941
  Lisp_Object window;
  register struct window *w;
  window = FRAME_SELECTED_WINDOW (f);
  w = XWINDOW (window);
942 943 944 945
  
  if (update_mode_lines)
    w->update_mode_line = Qt;

946
  if (
947
#ifdef USE_X_TOOLKIT
948
      FRAME_EXTERNAL_MENU_BAR (f) 
949
#else
950
      FRAME_MENU_BAR_LINES (f) > 0
951
#endif
952
      )
953 954 955 956 957 958 959 960 961
    {
      /* If the user has switched buffers or windows, we need to
	 recompute to reflect the new bindings.  But we'll
	 recompute when update_mode_lines is set too; that means
	 that people can use force-mode-line-update to request
	 that the menu bar be recomputed.  The adverse effect on
	 the rest of the redisplay algorithm is about the same as
	 windows_or_buffers_changed anyway.  */
      if (windows_or_buffers_changed
962
	  || !NILP (w->update_mode_line)
963 964 965 966 967
	  || (XFASTINT (w->last_modified) < MODIFF
	      && (XFASTINT (w->last_modified)
		  <= XBUFFER (w->buffer)->save_modified)))
	{
	  struct buffer *prev = current_buffer;
968
	  call1 (Vrun_hooks, Qmenu_bar_update_hook);
969
	  current_buffer = XBUFFER (w->buffer);
970
	  FRAME_MENU_BAR_ITEMS (f) = menu_bar_items (FRAME_MENU_BAR_ITEMS (f));
971
	  current_buffer = prev;
972
#ifdef USE_X_TOOLKIT
973
	  set_frame_menubar (f, 0);
974
#endif /* USE_X_TOOLKIT */
975 976 977 978
	}
    }
}

Jim Blandy's avatar
Jim Blandy committed
979 980
int do_id = 1;

981 982
/* Redisplay WINDOW and its subwindows and siblings.  */

Jim Blandy's avatar
Jim Blandy committed
983 984 985 986
static void
redisplay_windows (window)
     Lisp_Object window;
{
Jim Blandy's avatar
Jim Blandy committed
987
  for (; !NILP (window); window = XWINDOW (window)->next)
Jim Blandy's avatar
Jim Blandy committed
988 989 990
    redisplay_window (window, 0);
}

991 992
/* Redisplay window WINDOW and its subwindows.  */

Jim Blandy's avatar
Jim Blandy committed
993 994 995 996 997 998
static void
redisplay_window (window, just_this_one)
     Lisp_Object window;
     int just_this_one;
{
  register struct window *w = XWINDOW (window);
999
  FRAME_PTR f = XFRAME (WINDOW_FRAME (w));
Jim Blandy's avatar
Jim Blandy committed
1000
  int height;
Karl Heuer's avatar
Karl Heuer committed
1001
  register int lpoint = PT;
Jim Blandy's avatar
Jim Blandy committed
1002
  struct buffer *old = current_buffer;
1003
  register int width = window_internal_width (w) - 1;
Jim Blandy's avatar
Jim Blandy committed
1004 1005 1006
  register int startp;
  register int hscroll = XINT (w->hscroll);
  struct position pos;
Karl Heuer's avatar
Karl Heuer committed
1007
  int opoint = PT;
Jim Blandy's avatar
Jim Blandy committed
1008 1009 1010
  int tem;
  int window_needs_modeline;

Jim Blandy's avatar
Jim Blandy committed
1011
  if (FRAME_HEIGHT (f) == 0) abort (); /* Some bug zeros some core */
Jim Blandy's avatar
Jim Blandy committed
1012 1013 1014

  /* If this is a combination window, do its children; that's all.  */

Jim Blandy's avatar
Jim Blandy committed
1015
  if (!NILP (w->vchild))
Jim Blandy's avatar
Jim Blandy committed
1016 1017 1018 1019
    {
      redisplay_windows (w->vchild);
      return;
    }
Jim Blandy's avatar
Jim Blandy committed
1020
  if (!NILP (w->hchild))
Jim Blandy's avatar
Jim Blandy committed
1021 1022 1023 1024
    {
      redisplay_windows (w->hchild);
      return;
    }
Jim Blandy's avatar
Jim Blandy committed
1025
  if (NILP (w->buffer))
Jim Blandy's avatar
Jim Blandy committed
1026
    abort ();
Jim Blandy's avatar
Jim Blandy committed
1027 1028 1029 1030 1031 1032 1033 1034 1035
  
  height = window_internal_height (w);

  if (MINI_WINDOW_P (w))
    {
      if (w == XWINDOW (minibuf_window))
	{
	  if (echo_area_glyphs)
	    /* We've already displayed the echo area glyphs, if any.  */
1036
	    goto finish_scroll_bars;
Jim Blandy's avatar
Jim Blandy committed
1037 1038 1039 1040 1041
	}
      else
	{
	  /* This is a minibuffer, but it's not the currently active one, so
	     clear it.  */
Jim Blandy's avatar
Jim Blandy committed
1042
	  int vpos = XFASTINT (XWINDOW (FRAME_MINIBUF_WINDOW (f))->top);
Jim Blandy's avatar
Jim Blandy committed
1043 1044 1045 1046
	  int i;

	  for (i = 0; i < height; i++)
	    {
Jim Blandy's avatar
Jim Blandy committed
1047
	      get_display_line (f, vpos + i, 0);
1048
	      display_string (w, vpos + i, "", 0, 0, 0, 1, 0, width);
Jim Blandy's avatar
Jim Blandy committed
1049 1050
	    }
	  
1051
	  goto finish_scroll_bars;
Jim Blandy's avatar
Jim Blandy committed
1052 1053
	}
    }
Jim Blandy's avatar
Jim Blandy committed
1054 1055 1056 1057 1058 1059 1060

  if (update_mode_lines)
    w->update_mode_line = Qt;

  /* Otherwise set up data on this window; select its buffer and point value */

  current_buffer = XBUFFER (w->buffer);
Karl Heuer's avatar
Karl Heuer committed
1061
  opoint = PT;
Jim Blandy's avatar
Jim Blandy committed
1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073

  /* Count number of windows showing the selected buffer.  */

  if (!just_this_one
      && current_buffer == XBUFFER (XWINDOW (selected_window)->buffer))
    buffer_shared++;

  /* POINT refers normally to the selected window.
     For any other window, set up appropriate value.  */

  if (!EQ (window, selected_window))
    {
1074 1075
      int new_pt = marker_position (w->pointm);
      if (new_pt < BEGV)
Jim Blandy's avatar
Jim Blandy committed
1076
	{
1077 1078
	  new_pt = BEGV;
	  Fset_marker (w->pointm, make_number (new_pt), Qnil);
Jim Blandy's avatar
Jim Blandy committed
1079
	}
1080
      else if (new_pt > (ZV - 1))
Jim Blandy's avatar
Jim Blandy committed
1081
	{
1082 1083
	  new_pt = ZV;
	  Fset_marker (w->pointm, make_number (new_pt), Qnil);
Jim Blandy's avatar
Jim Blandy committed
1084
	}
1085 1086
      /* We don't use SET_PT so that the point-motion hooks don't run.  */
      BUF_PT (current_buffer) = new_pt;
Jim Blandy's avatar
Jim Blandy committed
1087 1088 1089 1090 1091 1092 1093 1094
    }

  /* If window-start is screwed up, choose a new one.  */
  if (XMARKER (w->start)->buffer != current_buffer)
    goto recenter;

  startp = marker_position (w->start);

Jim Blandy's avatar
Jim Blandy committed
1095
  /* Handle case where place to start displaying has been specified,
1096
     unless the specified location is outside the accessible range.  */
Jim Blandy's avatar
Jim Blandy committed
1097
  if (!NILP (w->force_start))
Jim Blandy's avatar
Jim Blandy committed
1098
    {
1099 1100
      /* Forget any recorded base line for line number display.  */
      w->base_line_number = Qnil;
Jim Blandy's avatar
Jim Blandy committed
1101 1102 1103
      w->update_mode_line = Qt;
      w->force_start = Qnil;
      XFASTINT (w->last_modified) = 0;
Jim Blandy's avatar
Jim Blandy committed
1104