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From: "Johan Bockgård" <bojohan@gnu.org>
To: 9495@debbugs.gnu.org
Subject: bug#9495: 24.0.50; Segfault in try_cursor_movement
Date: Tue, 13 Sep 2011 21:28:17 +0200	[thread overview]
Message-ID: <877h5ctf72.fsf@gnu.org> (raw)


Program terminated with signal 11, Segmentation fault.
#0  0x00007f5bccbe6fe7 in kill () at ../sysdeps/unix/syscall-template.S:82
82      ../sysdeps/unix/syscall-template.S: No such file or directory.
        in ../sysdeps/unix/syscall-template.S
(gdb) bt
#0  0x00007f5bccbe6fe7 in kill () at ../sysdeps/unix/syscall-template.S:82
#1  0x000000000056e889 in fatal_error_signal (sig=11) at emacs.c:358
#2  <signal handler called>
#3  0x0000000000465f3f in try_cursor_movement (window=20987605, startp=...,
    scroll_step=0x7fff5e400758) at xdisp.c:14639

xdisp.c:14639: (BUFFERP (g->object) && g->charpos == PT)

g is not a valid glyph here.

(gdb) p MATRIX_ROW (w->current_matrix, w->cursor.vpos).used[TEXT_AREA]
$3 = 80
(gdb) p w->cursor.hpos
$4 = 80


2011-09-13  Johan Bockgård  <bojohan@gnu.org>

	* xdisp.c (try_cursor_movement): Check bounds of hpos.

=== modified file 'src/xdisp.c'
--- src/xdisp.c	2011-09-09 01:06:52 +0000
+++ src/xdisp.c	2011-09-11 15:03:56 +0000
@@ -14627,7 +14627,11 @@ try_cursor_movement (Lisp_Object window,
 		     is set, we are done.  */
 		  at_zv_p =
 		    MATRIX_ROW (w->current_matrix, w->cursor.vpos)->ends_at_zv_p;
-		  if (!at_zv_p)
+		  if (!at_zv_p
+		      && w->cursor.hpos >= 0
+		      && (w->cursor.hpos
+			  < MATRIX_ROW_USED (w->current_matrix,
+					     w->cursor.vpos)))
 		    {
 		      struct glyph_row *candidate =
 			MATRIX_ROW (w->current_matrix, w->cursor.vpos);


BTW, is this code in try_window_reusing_current_matrix correct?

    struct glyph *glyph = row->glyphs[TEXT_AREA] + w->cursor.hpos;
    struct glyph *end = glyph + row->used[TEXT_AREA];

It doesn't seem right for end to depend on hpos.





             reply	other threads:[~2011-09-13 19:28 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-09-13 19:28 Johan Bockgård [this message]
2011-09-14  5:22 ` bug#9495: 24.0.50; Segfault in try_cursor_movement Eli Zaretskii
2011-09-14 19:50   ` Johan Bockgård
2011-09-15  3:12     ` Leo
2011-09-15  4:41       ` Eli Zaretskii
2011-09-15 16:05     ` Eli Zaretskii

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