[Emacs-diffs] /srv/bzr/emacs/emacs-24 r108012: Fix bug #11519 with relocation of buffer text during regex search.

[Eli Zaretskii]

------------------------------------------------------------
revno: 108012
fixes bug: http://debbugs.gnu.org/11519
committer: Eli Zaretskii <address@hidden>
branch nick: emacs-24
timestamp: Wed 2012-05-23 20:32:28 +0300
message:
  Fix bug #11519 with relocation of buffer text during regex search.
  
   src/lisp.h [REL_ALLOC]: Add prototypes for external functions
   defined on ralloc.c.
   src/buffer.c [REL_ALLOC]: Remove prototypes of
   r_alloc_reset_variable, r_alloc, r_re_alloc, and r_alloc_free,
   they are now on lisp.h.
   src/ralloc.c (r_alloc_inhibit_buffer_relocation): New function.
   src/search.c (search_buffer): Use it to inhibit relocation of buffer
   text while re_search_2 is doing its job, because re_search_2 is
   passed C pointers to buffer text.
modified:
  src/ChangeLog
  src/buffer.c
  src/lisp.h
  src/ralloc.c
  src/search.c

=== modified file 'src/ChangeLog'
--- a/src/ChangeLog     2012-05-21 19:56:36 +0000
+++ b/src/ChangeLog     2012-05-23 17:32:28 +0000
@@ -1,3 +1,18 @@
+2012-05-23  Eli Zaretskii  <address@hidden>
+
+       * lisp.h [REL_ALLOC]: Add prototypes for external functions
+       defined on ralloc.c.
+
+       * buffer.c [REL_ALLOC]: Remove prototypes of
+       r_alloc_reset_variable, r_alloc, r_re_alloc, and r_alloc_free,
+       they are now on lisp.h.
+
+       * ralloc.c (r_alloc_inhibit_buffer_relocation): New function.
+
+       * search.c (search_buffer): Use it to inhibit relocation of buffer
+       text while re_search_2 is doing its job, because re_search_2 is
+       passed C pointers to buffer text.  (Bug#11519)
+
 2012-05-21  Eli Zaretskii  <address@hidden>
 
        * msdos.c (internal_terminal_init) <Vwindow_system_version>:

=== modified file 'src/buffer.c'
--- a/src/buffer.c      2012-03-12 08:27:25 +0000
+++ b/src/buffer.c      2012-05-23 17:32:28 +0000
@@ -2014,10 +2014,6 @@
   return byte_pos;
 }
 
-#ifdef REL_ALLOC
-extern void r_alloc_reset_variable (POINTER_TYPE *, POINTER_TYPE *);
-#endif /* REL_ALLOC */
-
 DEFUN ("buffer-swap-text", Fbuffer_swap_text, Sbuffer_swap_text,
        1, 1, 0,
        doc: /* Swap the text between current buffer and BUFFER.  */)
@@ -4779,13 +4775,6 @@
                            Buffer-text Allocation
  ***********************************************************************/
 
-#ifdef REL_ALLOC
-extern POINTER_TYPE *r_alloc (POINTER_TYPE **, size_t);
-extern POINTER_TYPE *r_re_alloc (POINTER_TYPE **, size_t);
-extern void r_alloc_free (POINTER_TYPE **ptr);
-#endif /* REL_ALLOC */
-
-
 /* Allocate NBYTES bytes for buffer B's text buffer.  */
 
 static void

=== modified file 'src/lisp.h'
--- a/src/lisp.h        2012-03-12 06:34:32 +0000
+++ b/src/lisp.h        2012-05-23 17:32:28 +0000
@@ -3565,6 +3565,15 @@
 /* Defined in msdos.c, w32.c */
 extern char *emacs_root_dir (void);
 #endif /* DOS_NT */
+
+#ifdef REL_ALLOC
+/* Defined in ralloc.c */
+extern void r_alloc_reset_variable (POINTER_TYPE **, POINTER_TYPE **);
+extern POINTER_TYPE *r_alloc (POINTER_TYPE **, size_t);
+extern POINTER_TYPE *r_re_alloc (POINTER_TYPE **, size_t);
+extern void r_alloc_free (POINTER_TYPE **ptr);
+extern void r_alloc_inhibit_buffer_relocation (int);
+#endif /* REL_ALLOC */
 
 /* Nonzero means Emacs has already been initialized.
    Used during startup to detect startup of dumped Emacs.  */

=== modified file 'src/ralloc.c'
--- a/src/ralloc.c      2012-02-01 16:51:20 +0000
+++ b/src/ralloc.c      2012-05-23 17:32:28 +0000
@@ -1201,6 +1201,12 @@
   bloc->variable = new;
 }
 
+void
+r_alloc_inhibit_buffer_relocation (int inhibit)
+{
+  use_relocatable_buffers = !inhibit;
+}
+
 
 /***********************************************************************
                            Initialization

=== modified file 'src/search.c'
--- a/src/search.c      2012-03-27 06:46:42 +0000
+++ b/src/search.c      2012-05-23 17:32:28 +0000
@@ -1158,12 +1158,25 @@
       while (n < 0)
        {
          EMACS_INT val;
+
+#ifdef REL_ALLOC
+         /* re_search_2 below is passed C pointers to buffer text.
+            If some code called by it causes memory (re)allocation,
+            buffer text could be relocated on platforms that use
+            REL_ALLOC, which invalidates those C pointers.  So we
+            inhibit relocation of buffer text for as long as
+            re_search_2 runs.  */
+         r_alloc_inhibit_buffer_relocation (1);
+#endif
          val = re_search_2 (bufp, (char *) p1, s1, (char *) p2, s2,
                             pos_byte - BEGV_BYTE, lim_byte - pos_byte,
                             (NILP (Vinhibit_changing_match_data)
                              ? &search_regs : &search_regs_1),
                             /* Don't allow match past current point */
                             pos_byte - BEGV_BYTE);
+#ifdef REL_ALLOC
+         r_alloc_inhibit_buffer_relocation (0);
+#endif
          if (val == -2)
            {
              matcher_overflow ();
@@ -1202,11 +1215,20 @@
       while (n > 0)
        {
          EMACS_INT val;
+
+#ifdef REL_ALLOC
+         /* See commentary above for the reasons for inhibiting
+            buffer text relocation here.  */
+         r_alloc_inhibit_buffer_relocation (1);
+#endif
          val = re_search_2 (bufp, (char *) p1, s1, (char *) p2, s2,
                             pos_byte - BEGV_BYTE, lim_byte - pos_byte,
                             (NILP (Vinhibit_changing_match_data)
                              ? &search_regs : &search_regs_1),
                             lim_byte - BEGV_BYTE);
+#ifdef REL_ALLOC
+         r_alloc_inhibit_buffer_relocation (0);
+#endif
          if (val == -2)
            {
              matcher_overflow ();