webkit back function

6 files changed, 62 insertions, 23 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index c06c98c5418..484a4420363 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,25 @@
+2011-07-18  Paul Eggert  <eggert@cs.ucla.edu>
+
+        * fileio.c (Fcopy_file) [!MSDOS]: Tighten created file's mask.
+        This fixes some race conditions on the permissions of any newly
+        created file.
+
+        * alloc.c (valid_pointer_p): Use pipe, not open.
+        This fixes some permissions issues when debugging.
+
+        * fileio.c (Fcopy_file): Adjust mode if fchown fails.  (Bug#9002)
+        If fchown fails to set both uid and gid, try to set just gid,
+        as that is sometimes allowed.  Adjust the file's mode to eliminate
+        setuid or setgid bits that are inappropriate if fchown fails.
+
+2011-07-18  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+        * xdisp.c (next_element_from_string, next_element_from_buffer): Use EQ
+        to compare Lisp_Objects.
+        * gnutls.c (syms_of_gnutls): Rename Vgnutls_log_level to
+        global_gnutls_log_level, don't mistake it for a Lisp_Object.
+        (init_gnutls_functions, emacs_gnutls_handle_error): Fix up uses.
+
 2011-07-17  Andreas Schwab  <schwab@linux-m68k.org>
 
         * lread.c (read_integer): Unread even EOF character.
diff --git a/src/alloc.c b/src/alloc.c
index 44f935c243d..d48d1f34dbd 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -4415,18 +4415,18 @@ valid_pointer_p (void *p)
 #ifdef WINDOWSNT
   return w32_valid_pointer_p (p, 16);
 #else
-  int fd;
+  int fd[2];
 
   /* Obviously, we cannot just access it (we would SEGV trying), so we
      trick the o/s to tell us whether p is a valid pointer.
      Unfortunately, we cannot use NULL_DEVICE here, as emacs_write may
      not validate p in that case.  */
 
-  if ((fd = emacs_open ("__Valid__Lisp__Object__", O_CREAT | O_WRONLY | O_TRUNC, 0666)) >= 0)
+  if (pipe (fd) == 0)
     {
-      int valid = (emacs_write (fd, (char *)p, 16) == 16);
-      emacs_close (fd);
-      unlink ("__Valid__Lisp__Object__");
+      int valid = (emacs_write (fd[1], (char *) p, 16) == 16);
+      emacs_close (fd[1]);
+      emacs_close (fd[0]);
       return valid;
     }
 
diff --git a/src/fileio.c b/src/fileio.c
index a52e834c2b2..3e1aa54462f 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -38,8 +38,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <selinux/context.h>
 #endif
 
-#include <ignore-value.h>
-
 #include "lisp.h"
 #include "intervals.h"
 #include "buffer.h"
@@ -1939,10 +1937,19 @@ on the system, we copy the SELinux context of FILE to NEWNAME.  */)
                     | (NILP (ok_if_already_exists) ? O_EXCL : 0),
                     S_IREAD | S_IWRITE);
 #else  /* not MSDOS */
-  ofd = emacs_open (SSDATA (encoded_newname),
-                    O_WRONLY | O_TRUNC | O_CREAT
-                    | (NILP (ok_if_already_exists) ? O_EXCL : 0),
-                    0666);
+  {
+    int new_mask = 0666;
+    if (input_file_statable_p)
+      {
+        if (!NILP (preserve_uid_gid))
+          new_mask = 0600;
+        new_mask &= st.st_mode;
+      }
+    ofd = emacs_open (SSDATA (encoded_newname),
+                      (O_WRONLY | O_TRUNC | O_CREAT
+                       | (NILP (ok_if_already_exists) ? O_EXCL : 0)),
+                      new_mask);
+  }
 #endif /* not MSDOS */
   if (ofd < 0)
     report_file_error ("Opening output file", Fcons (newname, Qnil));
@@ -1961,9 +1968,21 @@ on the system, we copy the SELinux context of FILE to NEWNAME.  */)
      owner and group.  */
   if (input_file_statable_p)
     {
+      int mode_mask = 07777;
       if (!NILP (preserve_uid_gid))
-        ignore_value (fchown (ofd, st.st_uid, st.st_gid));
-      if (fchmod (ofd, st.st_mode & 07777) != 0)
+        {
+          /* Attempt to change owner and group.  If that doesn't work
+             attempt to change just the group, as that is sometimes allowed.
+             Adjust the mode mask to eliminate setuid or setgid bits
+             that are inappropriate if the owner and group are wrong.  */
+          if (fchown (ofd, st.st_uid, st.st_gid) != 0)
+            {
+              mode_mask &= ~06000;
+              if (fchown (ofd, -1, st.st_gid) == 0)
+                mode_mask |= 02000;
+            }
+        }
+      if (fchmod (ofd, st.st_mode & mode_mask) != 0)
         report_file_error ("Doing chmod", Fcons (newname, Qnil));
     }
 #endif  /* not MSDOS */
diff --git a/src/gnutls.c b/src/gnutls.c
index 52e80a69ae5..3175f55041d 100644
--- a/src/gnutls.c
+++ b/src/gnutls.c
@@ -193,8 +193,7 @@ init_gnutls_functions (Lisp_Object libraries)
   LOAD_GNUTLS_FN (library, gnutls_x509_crt_import);
   LOAD_GNUTLS_FN (library, gnutls_x509_crt_init);
 
-  if (NUMBERP (Vgnutls_log_level))
-    max_log_level = XINT (Vgnutls_log_level);
+  max_log_level = global_gnutls_log_level;
 
   GNUTLS_LOG2 (1, max_log_level, "GnuTLS library loaded:",
                SDATA (Fget (Qgnutls_dll, QCloaded_from)));
@@ -406,8 +405,7 @@ emacs_gnutls_handle_error (gnutls_session_t session, int err)
   if (err >= 0)
     return 0;
 
-  if (NUMBERP (Vgnutls_log_level))
-    max_log_level = XINT (Vgnutls_log_level);
+  max_log_level = global_gnutls_log_level;
 
   /* TODO: use gnutls-error-fatalp and gnutls-error-string.  */
 
@@ -1155,9 +1153,9 @@ syms_of_gnutls (void)
   defsubr (&Sgnutls_bye);
   defsubr (&Sgnutls_available_p);
 
-  DEFVAR_INT ("gnutls-log-level", Vgnutls_log_level,
-              doc: /* Logging level used by the GnuTLS functions. */);
-  Vgnutls_log_level = make_number (0);
+  DEFVAR_INT ("gnutls-log-level", global_gnutls_log_level,
+              doc: /* Logging level used by the GnuTLS functions.  */);
+  global_gnutls_log_level = 0;
 }
 
 #endif /* HAVE_GNUTLS */
diff --git a/src/process.h b/src/process.h
index 4866a8c1022..aff9e970f63 100644
--- a/src/process.h
+++ b/src/process.h
@@ -141,7 +141,7 @@ struct Lisp_Process
 /* Every field in the preceding structure except for the first two
    must be a Lisp_Object, for GC's sake.  */
 
-#define ChannelMask(n) (1<<(n))
+#define ChannelMask(n) (1 << (n))
 
 /* True if we are about to fork off a synchronous process or if we
    are waiting for it.  */
diff --git a/src/xdisp.c b/src/xdisp.c
index cd87d00d8d0..816c7d36ce3 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -6968,7 +6968,7 @@ next_element_from_string (struct it *it)
   struct text_pos position;
 
   xassert (STRINGP (it->string));
-  xassert (!it->bidi_p || it->string == it->bidi_it.string.lstring);
+  xassert (!it->bidi_p || EQ (it->string, it->bidi_it.string.lstring));
   xassert (IT_STRING_CHARPOS (*it) >= 0);
   position = it->current.string_pos;
 
@@ -7294,7 +7294,7 @@ next_element_from_buffer (struct it *it)
   xassert (IT_CHARPOS (*it) >= BEGV);
   xassert (NILP (it->string) && !it->s);
   xassert (!it->bidi_p
-           || (it->bidi_it.string.lstring == Qnil
+           || (EQ (it->bidi_it.string.lstring, Qnil)
                && it->bidi_it.string.s == NULL));
 
   /* With bidi reordering, the character to display might not be the